def gammabar__inverse_and_derivs():
# Step 4.a: Declare as globals all expressions that may be used
# outside this function, declare BSSN gridfunctions
# if not defined already, and set DIM=3.
global gammabarUU, gammabarDD_dD, gammabarDD_dupD, gammabarDD_dDD, GammabarUDD
hDD, aDD, lambdaU, vetU, betU, trK, cf, alpha = declare_BSSN_gridfunctions_if_not_declared_already(
)
DIM = 3
# This function needs gammabarDD, defined in BSSN_basic_tensors()
BSSN_basic_tensors()
# Step 4.a.i: gammabarUU:
gammabarUU, dummydet = ixp.symm_matrix_inverter3x3(gammabarDD)
# Step 4.b.i: gammabarDDdD[i][j][k]
# = \hat{\gamma}_{ij,k} + h_{ij,k} \text{ReDD[i][j]} + h_{ij} \text{ReDDdD[i][j][k]}.
gammabarDD_dD = ixp.zerorank3()
gammabarDD_dupD = ixp.zerorank3()
hDD_dD = ixp.declarerank3("hDD_dD", "sym01")
hDD_dupD = ixp.declarerank3("hDD_dupD", "sym01")
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
gammabarDD_dD[i][j][k] = rfm.ghatDDdD[i][j][k] + \
hDD_dD[i][j][k] * rfm.ReDD[i][j] + hDD[i][j] * rfm.ReDDdD[i][j][k]
# Compute associated upwinded derivative, needed for the \bar{\gamma}_{ij} RHS
gammabarDD_dupD[i][j][k] = rfm.ghatDDdD[i][j][k] + \
hDD_dupD[i][j][k] * rfm.ReDD[i][j] + hDD[i][j] * rfm.ReDDdD[i][j][k]
# Step 4.b.ii: Compute gammabarDD_dDD in terms of the rescaled BSSN quantity hDD
# and its derivatives, as well as the reference metric and rescaling
# matrix, and its derivatives (expression given below):
hDD_dDD = ixp.declarerank4("hDD_dDD", "sym01_sym23")
gammabarDD_dDD = ixp.zerorank4()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
for l in range(DIM):
# gammabar_{ij,kl} = gammahat_{ij,kl}
# + h_{ij,kl} ReDD[i][j]
# + h_{ij,k} ReDDdD[i][j][l] + h_{ij,l} ReDDdD[i][j][k]
# + h_{ij} ReDDdDD[i][j][k][l]
gammabarDD_dDD[i][j][k][l] = rfm.ghatDDdDD[i][j][k][l]
gammabarDD_dDD[i][j][k][
l] += hDD_dDD[i][j][k][l] * rfm.ReDD[i][j]
gammabarDD_dDD[i][j][k][l] += hDD_dD[i][j][k] * rfm.ReDDdD[i][j][l] + \
hDD_dD[i][j][l] * rfm.ReDDdD[i][j][k]
gammabarDD_dDD[i][j][k][
l] += hDD[i][j] * rfm.ReDDdDD[i][j][k][l]
# Step 4.b.iii: Define barred Christoffel symbol \bar{\Gamma}^{i}_{kl} = GammabarUDD[i][k][l] (see expression below)
GammabarUDD = ixp.zerorank3()
for i in range(DIM):
for k in range(DIM):
for l in range(DIM):
for m in range(DIM):
# Gammabar^i_{kl} = 1/2 * gammabar^{im} ( gammabar_{mk,l} + gammabar_{ml,k} - gammabar_{kl,m}):
GammabarUDD[i][k][l] += sp.Rational(1, 2) * gammabarUU[i][m] * \
(gammabarDD_dD[m][k][l] + gammabarDD_dD[m][l][k] - gammabarDD_dD[k][l][m])
def AbarUU_AbarUD_trAbar_AbarDD_dD():
# Step 6.a: Declare as globals all expressions that may be used
# outside this function, declare BSSN gridfunctions
# if not defined already, and set DIM=3.
global AbarUU, AbarUD, trAbar, AbarDD_dD, AbarDD_dupD
hDD, aDD, lambdaU, vetU, betU, trK, cf, alpha = declare_BSSN_gridfunctions_if_not_declared_already(
)
DIM = 3
# Define AbarDD and gammabarDD in terms of BSSN gridfunctions
BSSN_basic_tensors()
# Define gammabarUU in terms of BSSN gridfunctions
gammabar__inverse_and_derivs()
# Step 6.a.i: Compute Abar^{ij} in terms of Abar_{ij} and gammabar^{ij}
AbarUU = ixp.zerorank2()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
for l in range(DIM):
# Abar^{ij} = gammabar^{ik} gammabar^{jl} Abar_{kl}
AbarUU[i][j] += gammabarUU[i][k] * gammabarUU[j][
l] * AbarDD[k][l]
# Step 6.a.ii: Compute Abar^i_j in terms of Abar_{ij} and gammabar^{ij}
AbarUD = ixp.zerorank2()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
# Abar^i_j = gammabar^{ik} Abar_{kj}
AbarUD[i][j] += gammabarUU[i][k] * AbarDD[k][j]
# Step 6.a.iii: Compute Abar^k_k = trace of Abar:
trAbar = sp.sympify(0)
for k in range(DIM):
for j in range(DIM):
# Abar^k_k = gammabar^{kj} Abar_{jk}
trAbar += gammabarUU[k][j] * AbarDD[j][k]
# Step 6.a.iv: Compute Abar_{ij,k}
AbarDD_dD = ixp.zerorank3()
AbarDD_dupD = ixp.zerorank3()
aDD_dD = ixp.declarerank3("aDD_dD", "sym01")
aDD_dupD = ixp.declarerank3("aDD_dupD", "sym01")
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
AbarDD_dupD[i][j][k] = rfm.ReDDdD[i][j][k] * aDD[i][
j] + rfm.ReDD[i][j] * aDD_dupD[i][j][k]
AbarDD_dD[i][j][k] = rfm.ReDDdD[i][j][k] * aDD[i][
j] + rfm.ReDD[i][j] * aDD_dD[i][j][k]
def betaU_derivs():
# Step 8.i: Declare as globals all expressions that may be used
# outside this function, declare BSSN gridfunctions
# if not defined already, and set DIM=3.
global betaU_dD, betaU_dupD, betaU_dDD
hDD, aDD, lambdaU, vetU, betU, trK, cf, alpha = declare_BSSN_gridfunctions_if_not_declared_already(
)
DIM = 3
# Step 8.ii: Compute the unrescaled shift vector beta^i = ReU[i]*vet^i
vetU_dD = ixp.declarerank2("vetU_dD", "nosym")
vetU_dupD = ixp.declarerank2("vetU_dupD",
"nosym") # Needed for upwinded \beta^i_{,j}
vetU_dDD = ixp.declarerank3("vetU_dDD", "sym12") # Needed for \beta^i_{,j}
betaU_dD = ixp.zerorank2()
betaU_dupD = ixp.zerorank2() # Needed for, e.g., \beta^i RHS
betaU_dDD = ixp.zerorank3() # Needed for, e.g., \bar{\Lambda}^i RHS
for i in range(DIM):
for j in range(DIM):
betaU_dD[i][
j] = vetU_dD[i][j] * rfm.ReU[i] + vetU[i] * rfm.ReUdD[i][j]
betaU_dupD[i][j] = vetU_dupD[i][j] * rfm.ReU[i] + vetU[
i] * rfm.ReUdD[i][j] # Needed for \beta^i RHS
for k in range(DIM):
# Needed for, e.g., \bar{\Lambda}^i RHS:
betaU_dDD[i][j][k] = vetU_dDD[i][j][k] * rfm.ReU[i] + vetU_dD[i][j] * rfm.ReUdD[i][k] + \
vetU_dD[i][k] * rfm.ReUdD[i][j] + vetU[i] * rfm.ReUdDD[i][j][k]
def write_out_functions_for_StildeD_source_term(outdir,outCparams,gammaDD,betaU,alpha,ValenciavU,BU,sqrt4pi):
generate_memory_access_code()
# First, we declare some dummy tensors that we will use for the codegen.
gammaDDdD = ixp.declarerank3("gammaDDdD","sym01",DIM=3)
betaUdD = ixp.declarerank2("betaUdD","nosym",DIM=3)
alphadD = ixp.declarerank1("alphadD",DIM=3)
# We need to rerun a few of these functions with the reset lists to make sure these functions
# don't cheat by using analytic expressions
GRHD.compute_sqrtgammaDET(gammaDD)
GRHD.u4U_in_terms_of_ValenciavU__rescale_ValenciavU_by_applying_speed_limit(alpha, betaU, gammaDD, ValenciavU)
GRFFE.compute_smallb4U(gammaDD, betaU, alpha, GRHD.u4U_ito_ValenciavU, BU, sqrt4pi)
GRFFE.compute_smallbsquared(gammaDD, betaU, alpha, GRFFE.smallb4U)
GRFFE.compute_TEM4UU(gammaDD,betaU,alpha, GRFFE.smallb4U, GRFFE.smallbsquared,GRHD.u4U_ito_ValenciavU)
GRHD.compute_g4DD_zerotimederiv_dD(gammaDD,betaU,alpha, gammaDDdD,betaUdD,alphadD)
GRHD.compute_S_tilde_source_termD(alpha, GRHD.sqrtgammaDET,GRHD.g4DD_zerotimederiv_dD, GRFFE.TEM4UU)
for i in range(3):
desc = "Adds the source term to StildeD"+str(i)+"."
name = "calculate_StildeD"+str(i)+"_source_term"
outCfunction(
outfile = os.path.join(outdir,name+".h"), desc=desc, name=name,
params ="const paramstruct *params,const REAL *auxevol_gfs, REAL *rhs_gfs",
body = general_access \
+metric_deriv_access[i]\
+outputC(GRHD.S_tilde_source_termD[i],"Stilde_rhsD"+str(i),"returnstring",params=outCparams).replace("IDX4","IDX4S")\
+write_final_quantity[i],
loopopts ="InteriorPoints",
rel_path_for_Cparams=os.path.join("../"))
def generate_everything_for_UnitTesting():
# First define hydrodynamical quantities
u4U = ixp.declarerank1("u4U", DIM=4)
rho_b, P, epsilon = sp.symbols('rho_b P epsilon', real=True)
# Then ADM quantities
gammaDD = ixp.declarerank2("gammaDD", "sym01", DIM=3)
KDD = ixp.declarerank2("KDD", "sym01", DIM=3)
betaU = ixp.declarerank1("betaU", DIM=3)
alpha = sp.symbols('alpha', real=True)
# First compute stress-energy tensor T4UU and T4UD:
compute_T4UU(gammaDD, betaU, alpha, rho_b, P, epsilon, u4U)
compute_T4UD(gammaDD, betaU, alpha, T4UU)
# Next sqrt(gamma)
compute_sqrtgammaDET(gammaDD)
# Compute conservative variables in terms of primitive variables
compute_rho_star(alpha, sqrtgammaDET, rho_b, u4U)
compute_tau_tilde(alpha, sqrtgammaDET, T4UU, rho_star)
compute_S_tildeD(alpha, sqrtgammaDET, T4UD)
# Then compute v^i from u^mu
compute_vU_from_u4U__no_speed_limit(u4U)
# Next compute fluxes of conservative variables
compute_rho_star_fluxU(vU, rho_star)
compute_tau_tilde_fluxU(alpha, sqrtgammaDET, vU, T4UU, rho_star)
compute_S_tilde_fluxUD(alpha, sqrtgammaDET, T4UD)
# Then declare derivatives & compute g4DD_zerotimederiv_dD
gammaDD_dD = ixp.declarerank3("gammaDD_dD", "sym01", DIM=3)
betaU_dD = ixp.declarerank2("betaU_dD", "nosym", DIM=3)
alpha_dD = ixp.declarerank1("alpha_dD", DIM=3)
compute_g4DD_zerotimederiv_dD(gammaDD, betaU, alpha, gammaDD_dD, betaU_dD,
alpha_dD)
# Then compute source terms on tau_tilde and S_tilde equations
compute_s_source_term(KDD, betaU, alpha, sqrtgammaDET, alpha_dD, T4UU)
compute_S_tilde_source_termD(alpha, sqrtgammaDET, g4DD_zerotimederiv_dD,
T4UU)
# Then compute the 4-velocities in terms of an input Valencia 3-velocity testValenciavU[i]
testValenciavU = ixp.declarerank1("testValenciavU", DIM=3)
u4U_in_terms_of_ValenciavU__rescale_ValenciavU_by_applying_speed_limit(
alpha, betaU, gammaDD, testValenciavU)
# Finally compute the 4-velocities in terms of an input 3-velocity testvU[i] = u^i/u^0
testvU = ixp.declarerank1("testvU", DIM=3)
u4U_in_terms_of_vU__rescale_vU_by_applying_speed_limit(
alpha, betaU, gammaDD, testvU)
def generate_everything_for_UnitTesting():
# First define hydrodynamical quantities
u4U = ixp.declarerank1("u4U", DIM=4)
B_tildeU = ixp.declarerank1("B_tildeU", DIM=3)
# Then ADM quantities
gammaDD = ixp.declarerank2("gammaDD", "sym01", DIM=3)
betaU = ixp.declarerank1("betaU", DIM=3)
alpha = sp.symbols('alpha', real=True)
# Then numerical constant
sqrt4pi = sp.symbols('sqrt4pi', real=True)
# First compute stress-energy tensor T4UU and T4UD:
import GRHD.equations as GHeq
GHeq.compute_sqrtgammaDET(gammaDD)
compute_B_notildeU(GHeq.sqrtgammaDET, B_tildeU)
compute_smallb4U(gammaDD, betaU, alpha, u4U, B_notildeU, sqrt4pi)
compute_smallb4U_with_driftvU_for_FFE(gammaDD, betaU, alpha, u4U,
B_notildeU, sqrt4pi)
compute_smallbsquared(gammaDD, betaU, alpha, smallb4U)
compute_TEM4UU(gammaDD, betaU, alpha, smallb4U, smallbsquared, u4U)
compute_TEM4UD(gammaDD, betaU, alpha, TEM4UU)
# Compute conservative variables in terms of primitive variables
GHeq.compute_S_tildeD(alpha, GHeq.sqrtgammaDET, TEM4UD)
global S_tildeD
S_tildeD = GHeq.S_tildeD
# Next compute fluxes of conservative variables
GHeq.compute_S_tilde_fluxUD(alpha, GHeq.sqrtgammaDET, TEM4UD)
global S_tilde_fluxUD
S_tilde_fluxUD = GHeq.S_tilde_fluxUD
# Then declare derivatives & compute g4DDdD
gammaDD_dD = ixp.declarerank3("gammaDD_dD", "sym01", DIM=3)
betaU_dD = ixp.declarerank2("betaU_dD", "nosym", DIM=3)
alpha_dD = ixp.declarerank1("alpha_dD", DIM=3)
GHeq.compute_g4DD_zerotimederiv_dD(gammaDD, betaU, alpha, gammaDD_dD,
betaU_dD, alpha_dD)
# Finally compute source terms on tau_tilde and S_tilde equations
GHeq.compute_S_tilde_source_termD(alpha, GHeq.sqrtgammaDET,
GHeq.g4DD_zerotimederiv_dD, TEM4UU)
global S_tilde_source_termD
S_tilde_source_termD = GHeq.S_tilde_source_termD
def WeylScalars_Cartesian():
# We do not need the barred or hatted quantities calculated when using Cartesian coordinates.
# Instead, we declare the PHYSICAL metric and extrinsic curvature as grid functions.
gammaDD = ixp.register_gridfunctions_for_single_rank2(
"EVOL", "gammaDD", "sym01")
kDD = ixp.register_gridfunctions_for_single_rank2("EVOL", "kDD", "sym01")
gammaUU, detgamma = ixp.symm_matrix_inverter3x3(gammaDD)
output_scalars = par.parval_from_str("output_scalars")
global psi4r, psi4i, psi3r, psi3i, psi2r, psi2i, psi1r, psi1i, psi0r, psi0i
# if output_scalars is "all_psis_and_invariants":
# psi4r,psi4i,psi3r,psi3i,psi2r,psi2i,psi1r,psi1i,psi0r,psi0i = sp.symbols("psi4r psi4i\
# psi3r psi3i\
# psi2r psi2i\
# psi1r psi1i\
# psi0r psi0i")
# elif output_scalars is "all_psis":
psi4r,psi4i,psi3r,psi3i,psi2r,psi2i,psi1r,psi1i,psi0r,psi0i = gri.register_gridfunctions("AUX",["psi4r","psi4i",\
"psi3r","psi3i",\
"psi2r","psi2i",\
"psi1r","psi1i",\
"psi0r","psi0i"])
# Step 2a: Set spatial dimension (must be 3 for BSSN)
DIM = 3
par.set_parval_from_str("grid::DIM", DIM)
# Step 2b: Set the coordinate system to Cartesian
x, y, z = gri.register_gridfunctions("AUX", ["x", "y", "z"])
# Step 2c: Set which tetrad is used; at the moment, only one supported option
if par.parval_from_str("WeylScal4NRPy.WeylScalars_Cartesian::TetradChoice"
) == "Approx_QuasiKinnersley":
# Step 3a: Choose 3 orthogonal vectors. Here, we choose one in the azimuthal
# direction, one in the radial direction, and the cross product of the two.
# Eqs 5.6, 5.7 in https://arxiv.org/pdf/gr-qc/0104063.pdf:
# v_1^a &= [-y,x,0] \\
# v_2^a &= [x,y,z] \\
# v_3^a &= {\rm det}(g)^{1/2} g^{ad} \epsilon_{dbc} v_1^b v_2^c,
v1U = ixp.zerorank1()
v2U = ixp.zerorank1()
v3U = ixp.zerorank1()
v1U[0] = -y
v1U[1] = x
v1U[2] = sp.sympify(0)
v2U[0] = x
v2U[1] = y
v2U[2] = z
LeviCivitaSymbol_rank3 = define_LeviCivitaSymbol_rank3()
for a in range(DIM):
for b in range(DIM):
for c in range(DIM):
for d in range(DIM):
v3U[a] += sp.sqrt(
detgamma) * gammaUU[a][d] * LeviCivitaSymbol_rank3[
d][b][c] * v1U[b] * v2U[c]
# Step 3b: Gram-Schmidt orthonormalization of the vectors.
# The w_i^a vectors here are used to temporarily hold values on the way to the final vectors e_i^a
# e_1^a &= \frac{v_1^a}{\omega_{11}} \\
# e_2^a &= \frac{v_2^a - \omega_{12} e_1^a}{\omega_{22}} \\
# e_3^a &= \frac{v_3^a - \omega_{13} e_1^a - \omega_{23} e_2^a}{\omega_{33}}, \\
# Normalize the first vector
w1U = ixp.zerorank1()
for a in range(DIM):
w1U[a] = v1U[a]
omega11 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega11 += w1U[a] * w1U[b] * gammaDD[a][b]
e1U = ixp.zerorank1()
for a in range(DIM):
e1U[a] = w1U[a] / sp.sqrt(omega11)
# Subtract off the portion of the first vector along the second, then normalize
omega12 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega12 += e1U[a] * v2U[b] * gammaDD[a][b]
w2U = ixp.zerorank1()
for a in range(DIM):
w2U[a] = v2U[a] - omega12 * e1U[a]
omega22 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega22 += w2U[a] * w2U[b] * gammaDD[a][b]
e2U = ixp.zerorank1()
for a in range(DIM):
e2U[a] = w2U[a] / sp.sqrt(omega22)
# Subtract off the portion of the first and second vectors along the third, then normalize
omega13 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega13 += e1U[a] * v3U[b] * gammaDD[a][b]
omega23 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega23 += e2U[a] * v3U[b] * gammaDD[a][b]
w3U = ixp.zerorank1()
for a in range(DIM):
w3U[a] = v3U[a] - omega13 * e1U[a] - omega23 * e2U[a]
omega33 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega33 += w3U[a] * w3U[b] * gammaDD[a][b]
e3U = ixp.zerorank1()
for a in range(DIM):
e3U[a] = w3U[a] / sp.sqrt(omega33)
# Step 3c: Construct the tetrad itself.
# Eqs. 5.6:
# l^a &= \frac{1}{\sqrt{2}} e_2^a \\
# n^a &= -\frac{1}{\sqrt{2}} e_2^a \\
# m^a &= \frac{1}{\sqrt{2}} (e_3^a + i e_1^a) \\
# \overset{*}{m}{}^a &= \frac{1}{\sqrt{2}} (e_3^a - i e_1^a)
isqrt2 = 1 / sp.sqrt(2)
ltetU = ixp.zerorank1()
ntetU = ixp.zerorank1()
#mtetU = ixp.zerorank1()
#mtetccU = ixp.zerorank1()
remtetU = ixp.zerorank1(
) # SymPy does not like trying to take the real/imaginary parts of such a
immtetU = ixp.zerorank1(
) # complicated expression as the Weyl scalars, so we will do it ourselves.
for i in range(DIM):
ltetU[i] = isqrt2 * e2U[i]
ntetU[i] = -isqrt2 * e2U[i]
remtetU[i] = isqrt2 * e3U[i]
immtetU[i] = isqrt2 * e1U[i]
nn = isqrt2
else:
print("Error: TetradChoice == " + par.parval_from_str("TetradChoice") +
" unsupported!")
exit(1)
gammaDD_dD = ixp.declarerank3("gammaDD_dD", "sym01")
# Define the Christoffel symbols
GammaUDD = ixp.zerorank3(DIM)
for i in range(DIM):
for k in range(DIM):
for l in range(DIM):
for m in range(DIM):
GammaUDD[i][k][l] += (sp.Rational(1,2))*gammaUU[i][m]*\
(gammaDD_dD[m][k][l] + gammaDD_dD[m][l][k] - gammaDD_dD[k][l][m])
# Step 4b: Declare and construct the Riemann curvature tensor:
# R_{abcd} = \frac{1}{2} (\gamma_{ad,cb}+\gamma_{bc,da}-\gamma_{ac,bd}-\gamma_{bd,ac})
# + \gamma_{je} \Gamma^{j}_{bc}\Gamma^{e}_{ad} - \gamma_{je} \Gamma^{j}_{bd} \Gamma^{e}_{ac}
gammaDD_dDD = ixp.declarerank4("gammaDD_dDD", "sym01_sym23")
RiemannDDDD = ixp.zerorank4()
for a in range(DIM):
for b in range(DIM):
for c in range(DIM):
for d in range(DIM):
RiemannDDDD[a][b][c][d] = (gammaDD_dDD[a][d][c][b] + \
gammaDD_dDD[b][c][d][a] - \
gammaDD_dDD[a][c][b][d] - \
gammaDD_dDD[b][d][a][c]) / 2
for e in range(DIM):
for j in range(DIM):
RiemannDDDD[a][b][c][d] += gammaDD[j][e] * GammaUDD[j][b][c] * GammaUDD[e][a][d] - \
gammaDD[j][e] * GammaUDD[j][b][d] * GammaUDD[e][a][c]
# Step 4c: We also need the extrinsic curvature tensor $K_{ij}$.
# In Cartesian coordinates, we already made the components gridfunctions.
# We will, however, need to calculate the trace of K seperately:
trK = sp.sympify(0)
for i in range(DIM):
for j in range(DIM):
trK += gammaUU[i][j] * kDD[i][j]
# Step 5: Build the formula for \psi_4.
# Gauss equation: involving the Riemann tensor and extrinsic curvature.
# GaussDDDD[i][j][k][l] =& R_{ijkl} + 2K_{i[k}K_{l]j}
GaussDDDD = ixp.zerorank4()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
for l in range(DIM):
GaussDDDD[i][j][k][l] = RiemannDDDD[i][j][k][
l] + kDD[i][k] * kDD[l][j] - kDD[i][l] * kDD[k][j]
# Codazzi equation: involving partial derivatives of the extrinsic curvature.
# We will first need to declare derivatives of kDD
# CodazziDDD[j][k][l] =& -2 (K_{j[k,l]} + \Gamma^p_{j[k} K_{l]p})
kDD_dD = ixp.declarerank3("kDD_dD", "sym01")
CodazziDDD = ixp.zerorank3()
for j in range(DIM):
for k in range(DIM):
for l in range(DIM):
CodazziDDD[j][k][l] = kDD_dD[j][l][k] - kDD_dD[j][k][l]
for p in range(DIM):
CodazziDDD[j][k][l] += GammaUDD[p][j][l] * kDD[k][
p] - GammaUDD[p][j][k] * kDD[l][p]
# Another piece. While not associated with any particular equation,
# this is still useful for organizational purposes.
# RojoDD[j][l]} = & R_{jl} - K_{jp} K^p_l + KK_{jl} \\
# = & \gamma^{pd} R_{jpld} - K_{jp} K^p_l + KK_{jl}
RojoDD = ixp.zerorank2()
for j in range(DIM):
for l in range(DIM):
RojoDD[j][l] = trK * kDD[j][l]
for p in range(DIM):
for d in range(DIM):
RojoDD[j][l] += gammaUU[p][d] * RiemannDDDD[j][p][l][
d] - kDD[j][p] * gammaUU[p][d] * kDD[d][l]
# Now we can calculate $\psi_4$ itself! We assume l^0 = n^0 = \frac{1}{\sqrt{2}}
# and m^0 = \overset{*}{m}{}^0 = 0 to simplify these equations.
# We calculate the Weyl scalars as defined in https://arxiv.org/abs/gr-qc/0104063
# In terms of the above-defined quantites, the psis are defined as:
# \psi_4 =&\ (\text{GaussDDDD[i][j][k][l]}) n^i \overset{*}{m}{}^j n^k \overset{*}{m}{}^l \\
# &+2 (\text{CodazziDDD[j][k][l]}) n^{0} \overset{*}{m}{}^{j} n^k \overset{*}{m}{}^l \\
# &+ (\text{RojoDD[j][l]}) n^{0} \overset{*}{m}{}^{j} n^{0} \overset{*}{m}{}^{l}.
# \psi_3 =&\ (\text{GaussDDDD[i][j][k][l]}) l^i n^j \overset{*}{m}{}^k n^l \\
# &+ (\text{CodazziDDD[j][k][l]}) (l^{0} n^{j} \overset{*}{m}{}^k n^l - l^{j} n^{0} \overset{*}{m}{}^k n^l - l^k n^j\overset{*}{m}{}^l n^0) \\
# &- (\text{RojoDD[j][l]}) l^{0} n^{j} \overset{*}{m}{}^l n^0 - l^{j} n^{0} \overset{*}{m}{}^l n^0 \\
# \psi_2 =&\ (\text{GaussDDDD[i][j][k][l]}) l^i m^j \overset{*}{m}{}^k n^l \\
# &+ (\text{CodazziDDD[j][k][l]}) (l^{0} m^{j} \overset{*}{m}{}^k n^l - l^{j} m^{0} \overset{*}{m}{}^k n^l - l^k m^l \overset{*}{m}{}^l n^0) \\
# &- (\text{RojoDD[j][l]}) l^0 m^j \overset{*}{m}{}^l n^0 \\
# \psi_1 =&\ (\text{GaussDDDD[i][j][k][l]}) n^i l^j m^k l^l \\
# &+ (\text{CodazziDDD[j][k][l]}) (n^{0} l^{j} m^k l^l - n^{j} l^{0} m^k l^l - n^k l^l m^j l^0) \\
# &- (\text{RojoDD[j][l]}) (n^{0} l^{j} m^l l^0 - n^{j} l^{0} m^l l^0) \\
# \psi_0 =&\ (\text{GaussDDDD[i][j][k][l]}) l^i m^j l^k m^l \\
# &+2 (\text{CodazziDDD[j][k][l]}) (l^0 m^j l^k m^l + l^k m^l l^0 m^j) \\
# &+ (\text{RojoDD[j][l]}) l^0 m^j l^0 m^j. \\
psi4r = sp.sympify(0)
psi4i = sp.sympify(0)
psi3r = sp.sympify(0)
psi3i = sp.sympify(0)
psi2r = sp.sympify(0)
psi2i = sp.sympify(0)
psi1r = sp.sympify(0)
psi1i = sp.sympify(0)
psi0r = sp.sympify(0)
psi0i = sp.sympify(0)
for l in range(DIM):
for j in range(DIM):
psi4r += RojoDD[j][l] * nn * nn * (remtetU[j] * remtetU[l] -
immtetU[j] * immtetU[l])
psi4i += RojoDD[j][l] * nn * nn * (-remtetU[j] * immtetU[l] -
immtetU[j] * remtetU[l])
psi3r += -RojoDD[j][l] * nn * nn * (ntetU[j] -
ltetU[j]) * remtetU[l]
psi3i += RojoDD[j][l] * nn * nn * (ntetU[j] -
ltetU[j]) * immtetU[l]
psi2r += -RojoDD[j][l] * nn * nn * (remtetU[l] * remtetU[j] +
immtetU[j] * immtetU[l])
psi2i += -RojoDD[j][l] * nn * nn * (immtetU[l] * remtetU[j] -
remtetU[j] * immtetU[l])
psi1r += RojoDD[j][l] * nn * nn * (ntetU[j] * remtetU[l] -
ltetU[j] * remtetU[l])
psi1i += RojoDD[j][l] * nn * nn * (ntetU[j] * immtetU[l] -
ltetU[j] * immtetU[l])
psi0r += RojoDD[j][l] * nn * nn * (remtetU[j] * remtetU[l] -
immtetU[j] * immtetU[l])
psi0i += RojoDD[j][l] * nn * nn * (remtetU[j] * immtetU[l] +
immtetU[j] * remtetU[l])
for l in range(DIM):
for j in range(DIM):
for k in range(DIM):
psi4r += 2 * CodazziDDD[j][k][l] * ntetU[k] * nn * (
remtetU[j] * remtetU[l] - immtetU[j] * immtetU[l])
psi4i += 2 * CodazziDDD[j][k][l] * ntetU[k] * nn * (
-remtetU[j] * immtetU[l] - immtetU[j] * remtetU[l])
psi3r += 1 * CodazziDDD[j][k][l] * nn * (
(ntetU[j] - ltetU[j]) * remtetU[k] * ntetU[l] -
remtetU[j] * ltetU[k] * ntetU[l])
psi3i += -1 * CodazziDDD[j][k][l] * nn * (
(ntetU[j] - ltetU[j]) * immtetU[k] * ntetU[l] -
immtetU[j] * ltetU[k] * ntetU[l])
psi2r += 1 * CodazziDDD[j][k][l] * nn * (
ntetU[l] *
(remtetU[j] * remtetU[k] + immtetU[j] * immtetU[k]) -
ltetU[k] *
(remtetU[j] * remtetU[l] + immtetU[j] * immtetU[l]))
psi2i += 1 * CodazziDDD[j][k][l] * nn * (
ntetU[l] *
(immtetU[j] * remtetU[k] - remtetU[j] * immtetU[k]) -
ltetU[k] *
(remtetU[j] * immtetU[l] - immtetU[j] * remtetU[l]))
psi1r += 1 * CodazziDDD[j][k][l] * nn * (
ltetU[j] * remtetU[k] * ltetU[l] - remtetU[j] * ntetU[k] *
ltetU[l] - ntetU[j] * remtetU[k] * ltetU[l])
psi1i += 1 * CodazziDDD[j][k][l] * nn * (
ltetU[j] * immtetU[k] * ltetU[l] - immtetU[j] * ntetU[k] *
ltetU[l] - ntetU[j] * immtetU[k] * ltetU[l])
psi0r += 2 * CodazziDDD[j][k][l] * nn * ltetU[k] * (
remtetU[j] * remtetU[l] - immtetU[j] * immtetU[l])
psi0i += 2 * CodazziDDD[j][k][l] * nn * ltetU[k] * (
remtetU[j] * immtetU[l] + immtetU[j] * remtetU[l])
for l in range(DIM):
for j in range(DIM):
for k in range(DIM):
for i in range(DIM):
psi4r += GaussDDDD[i][j][k][l] * ntetU[i] * ntetU[k] * (
remtetU[j] * remtetU[l] - immtetU[j] * immtetU[l])
psi4i += GaussDDDD[i][j][k][l] * ntetU[i] * ntetU[k] * (
-remtetU[j] * immtetU[l] - immtetU[j] * remtetU[l])
psi3r += GaussDDDD[i][j][k][l] * ltetU[i] * ntetU[
j] * remtetU[k] * ntetU[l]
psi3i += -GaussDDDD[i][j][k][l] * ltetU[i] * ntetU[
j] * immtetU[k] * ntetU[l]
psi2r += GaussDDDD[i][j][k][l] * ltetU[i] * ntetU[l] * (
remtetU[j] * remtetU[k] + immtetU[j] * immtetU[k])
psi2i += GaussDDDD[i][j][k][l] * ltetU[i] * ntetU[l] * (
immtetU[j] * remtetU[k] - remtetU[j] * immtetU[k])
psi1r += GaussDDDD[i][j][k][l] * ntetU[i] * ltetU[
j] * remtetU[k] * ltetU[l]
psi1i += GaussDDDD[i][j][k][l] * ntetU[i] * ltetU[
j] * immtetU[k] * ltetU[l]
psi0r += GaussDDDD[i][j][k][l] * ltetU[i] * ltetU[k] * (
remtetU[j] * remtetU[l] - immtetU[j] * immtetU[l])
psi0i += GaussDDDD[i][j][k][l] * ltetU[i] * ltetU[k] * (
remtetU[j] * immtetU[l] + immtetU[j] * remtetU[l])
def RicciBar__gammabarDD_dHatD__DGammaUDD__DGammaU():
# Step 7.a: Declare as globals all expressions that may be used
# outside this function, declare BSSN gridfunctions
# if not defined already, and set DIM=3.
global RbarDD, DGammaUDD, gammabarDD_dHatD, DGammaU
hDD, aDD, lambdaU, vetU, betU, trK, cf, alpha = declare_BSSN_gridfunctions_if_not_declared_already(
)
DIM = 3
# GammabarUDD is used below, defined in
# gammabar__inverse_and_derivs()
gammabar__inverse_and_derivs()
# Step 7.a.i: Define \varepsilon_{ij} = epsDD[i][j]
epsDD = ixp.zerorank3()
for i in range(DIM):
for j in range(DIM):
epsDD[i][j] = hDD[i][j] * rfm.ReDD[i][j]
# Step 7.a.ii: Define epsDD_dD[i][j][k]
hDD_dD = ixp.declarerank3("hDD_dD", "sym01")
epsDD_dD = ixp.zerorank3()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
epsDD_dD[i][j][k] = hDD_dD[i][j][k] * rfm.ReDD[i][j] + hDD[i][
j] * rfm.ReDDdD[i][j][k]
# Step 7.a.iii: Define epsDD_dDD[i][j][k][l]
hDD_dDD = ixp.declarerank4("hDD_dDD", "sym01_sym23")
epsDD_dDD = ixp.zerorank4()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
for l in range(DIM):
epsDD_dDD[i][j][k][l] = hDD_dDD[i][j][k][l] * rfm.ReDD[i][j] + \
hDD_dD[i][j][k] * rfm.ReDDdD[i][j][l] + \
hDD_dD[i][j][l] * rfm.ReDDdD[i][j][k] + \
hDD[i][j] * rfm.ReDDdDD[i][j][k][l]
# Step 7.a.iv: DhatgammabarDDdD[i][j][l] = \bar{\gamma}_{ij;\hat{l}}
# \bar{\gamma}_{ij;\hat{l}} = \varepsilon_{i j,l}
# - \hat{\Gamma}^m_{i l} \varepsilon_{m j}
# - \hat{\Gamma}^m_{j l} \varepsilon_{i m}
gammabarDD_dHatD = ixp.zerorank3()
for i in range(DIM):
for j in range(DIM):
for l in range(DIM):
gammabarDD_dHatD[i][j][l] = epsDD_dD[i][j][l]
for m in range(DIM):
gammabarDD_dHatD[i][j][l] += - rfm.GammahatUDD[m][i][l] * epsDD[m][j] \
- rfm.GammahatUDD[m][j][l] * epsDD[i][m]
# Step 7.a.v: \bar{\gamma}_{ij;\hat{l},k} = DhatgammabarDD_dHatD_dD[i][j][l][k]:
# \bar{\gamma}_{ij;\hat{l},k} = \varepsilon_{ij,lk}
# - \hat{\Gamma}^m_{i l,k} \varepsilon_{m j}
# - \hat{\Gamma}^m_{i l} \varepsilon_{m j,k}
# - \hat{\Gamma}^m_{j l,k} \varepsilon_{i m}
# - \hat{\Gamma}^m_{j l} \varepsilon_{i m,k}
gammabarDD_dHatD_dD = ixp.zerorank4()
for i in range(DIM):
for j in range(DIM):
for l in range(DIM):
for k in range(DIM):
gammabarDD_dHatD_dD[i][j][l][k] = epsDD_dDD[i][j][l][k]
for m in range(DIM):
gammabarDD_dHatD_dD[i][j][l][k] += -rfm.GammahatUDDdD[m][i][l][k] * epsDD[m][j] \
- rfm.GammahatUDD[m][i][l] * epsDD_dD[m][j][k] \
- rfm.GammahatUDDdD[m][j][l][k] * epsDD[i][m] \
- rfm.GammahatUDD[m][j][l] * epsDD_dD[i][m][k]
# Step 7.a.vi: \bar{\gamma}_{ij;\hat{l}\hat{k}} = DhatgammabarDD_dHatDD[i][j][l][k]
# \bar{\gamma}_{ij;\hat{l}\hat{k}} = \partial_k \hat{D}_{l} \varepsilon_{i j}
# - \hat{\Gamma}^m_{lk} \left(\hat{D}_{m} \varepsilon_{i j}\right)
# - \hat{\Gamma}^m_{ik} \left(\hat{D}_{l} \varepsilon_{m j}\right)
# - \hat{\Gamma}^m_{jk} \left(\hat{D}_{l} \varepsilon_{i m}\right)
gammabarDD_dHatDD = ixp.zerorank4()
for i in range(DIM):
for j in range(DIM):
for l in range(DIM):
for k in range(DIM):
gammabarDD_dHatDD[i][j][l][k] = gammabarDD_dHatD_dD[i][j][
l][k]
for m in range(DIM):
gammabarDD_dHatDD[i][j][l][k] += - rfm.GammahatUDD[m][l][k] * gammabarDD_dHatD[i][j][m] \
- rfm.GammahatUDD[m][i][k] * gammabarDD_dHatD[m][j][l] \
- rfm.GammahatUDD[m][j][k] * gammabarDD_dHatD[i][m][l]
# Step 7.b: Second term of RhatDD: compute \hat{D}_{j} \bar{\Lambda}^{k} = LambarU_dHatD[k][j]
lambdaU_dD = ixp.declarerank2("lambdaU_dD", "nosym")
LambarU_dHatD = ixp.zerorank2()
for j in range(DIM):
for k in range(DIM):
LambarU_dHatD[k][j] = lambdaU_dD[k][j] * rfm.ReU[k] + lambdaU[
k] * rfm.ReUdD[k][j]
for m in range(DIM):
LambarU_dHatD[k][
j] += rfm.GammahatUDD[k][m][j] * lambdaU[m] * rfm.ReU[m]
# Step 7.c: Conformal Ricci tensor, part 3: The \Delta^{k} \Delta_{(i j) k}
# + \bar{\gamma}^{k l}*(2 \Delta_{k(i}^{m} \Delta_{j) m l}
# + \Delta_{i k}^{m} \Delta_{m j l}) terms
# Step 7.c.i: Define \Delta^i_{jk} = \bar{\Gamma}^i_{jk} - \hat{\Gamma}^i_{jk} = DGammaUDD[i][j][k]
DGammaUDD = ixp.zerorank3()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
DGammaUDD[i][j][
k] = GammabarUDD[i][j][k] - rfm.GammahatUDD[i][j][k]
# Step 7.c.ii: Define \Delta^i = \bar{\gamma}^{jk} \Delta^i_{jk}
DGammaU = ixp.zerorank1()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
DGammaU[i] += gammabarUU[j][k] * DGammaUDD[i][j][k]
# Step 7.c.iii: Define \Delta_{ijk} = \bar{\gamma}_{im} \Delta^m_{jk}
DGammaDDD = ixp.zerorank3()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
for m in range(DIM):
DGammaDDD[i][j][k] += gammabarDD[i][m] * DGammaUDD[m][j][k]
if par.parval_from_str(thismodule + "::LeaveRicciSymbolic") == "True":
for i in range(len(gri.glb_gridfcs_list)):
if "RbarDD00" in gri.glb_gridfcs_list[i].name:
return
RbarDD = ixp.register_gridfunctions_for_single_rank2(
"AUXEVOL", "RbarDD", "sym01")
return
# Step 7.d: Summing the terms and defining \bar{R}_{ij}
# Step 7.d.i: Add the first term to RbarDD:
# Rbar_{ij} += - \frac{1}{2} \bar{\gamma}^{k l} \hat{D}_{k} \hat{D}_{l} \bar{\gamma}_{i j}
RbarDD = ixp.zerorank2()
RbarDDpiece = ixp.zerorank2()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
for l in range(DIM):
RbarDD[i][j] += -sp.Rational(1, 2) * gammabarUU[k][
l] * gammabarDD_dHatDD[i][j][l][k]
RbarDDpiece[i][j] += -sp.Rational(1, 2) * gammabarUU[k][
l] * gammabarDD_dHatDD[i][j][l][k]
# Step 7.d.ii: Add the second term to RbarDD:
# Rbar_{ij} += (1/2) * (gammabar_{ki} Lambar^k_{;\hat{j}} + gammabar_{kj} Lambar^k_{;\hat{i}})
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
RbarDD[i][j] += sp.Rational(
1, 2) * (gammabarDD[k][i] * LambarU_dHatD[k][j] +
gammabarDD[k][j] * LambarU_dHatD[k][i])
# Step 7.d.iii: Add the remaining term to RbarDD:
# Rbar_{ij} += \Delta^{k} \Delta_{(i j) k} = 1/2 \Delta^{k} (\Delta_{i j k} + \Delta_{j i k})
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
RbarDD[i][j] += sp.Rational(1, 2) * DGammaU[k] * (
DGammaDDD[i][j][k] + DGammaDDD[j][i][k])
# Step 7.d.iv: Add the final term to RbarDD:
# Rbar_{ij} += \bar{\gamma}^{k l} (\Delta^{m}_{k i} \Delta_{j m l}
# + \Delta^{m}_{k j} \Delta_{i m l}
# + \Delta^{m}_{i k} \Delta_{m j l})
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
for l in range(DIM):
for m in range(DIM):
RbarDD[i][j] += gammabarUU[k][l] * (
DGammaUDD[m][k][i] * DGammaDDD[j][m][l] +
DGammaUDD[m][k][j] * DGammaDDD[i][m][l] +
DGammaUDD[m][i][k] * DGammaDDD[m][j][l])
def GiRaFFE_Higher_Order_v2():
#Step 1.0: Set the spatial dimension parameter to 3.
par.set_parval_from_str("grid::DIM", 3)
DIM = par.parval_from_str("grid::DIM")
# Step 1.1: Set the finite differencing order to 4.
#par.set_parval_from_str("finite_difference::FD_CENTDERIVS_ORDER", 4)
thismodule = "GiRaFFE_NRPy"
# M_PI will allow the C code to substitute the correct value
M_PI = par.Cparameters("#define",thismodule,"M_PI","")
# ADMBase defines the 4-metric in terms of the 3+1 spacetime metric quantities gamma_{ij}, beta^i, and alpha
gammaDD = ixp.register_gridfunctions_for_single_rank2("AUX","gammaDD", "sym01",DIM=3)
betaU = ixp.register_gridfunctions_for_single_rank1("AUX","betaU",DIM=3)
alpha = gri.register_gridfunctions("AUX","alpha")
# GiRaFFE uses the Valencia 3-velocity and A_i, which are defined in the initial data module(GiRaFFEfood)
ValenciavU = ixp.register_gridfunctions_for_single_rank1("AUX","ValenciavU",DIM=3)
AD = ixp.register_gridfunctions_for_single_rank1("EVOL","AD",DIM=3)
# B^i must be computed at each timestep within GiRaFFE so that the Valencia 3-velocity can be evaluated
BU = ixp.register_gridfunctions_for_single_rank1("AUX","BU",DIM=3)
# <a id='step3'></a>
#
# ## Step 1.2: Build the four metric $g_{\mu\nu}$, its inverse $g^{\mu\nu}$ and spatial derivatives $g_{\mu\nu,i}$ from ADM 3+1 quantities $\gamma_{ij}$, $\beta^i$, and $\alpha$ \[Back to [top](#top)\]
#
# Notice that the time evolution equation for $\tilde{S}_i$
# $$
# \partial_t \tilde{S}_i = - \partial_j \left( \alpha \sqrt{\gamma} T^j_{{\rm EM} i} \right) + \frac{1}{2} \alpha \sqrt{\gamma} T^{\mu \nu}_{\rm EM} \partial_i g_{\mu \nu}
# $$
# contains $\partial_i g_{\mu \nu} = g_{\mu\nu,i}$. We will now focus on evaluating this term.
#
# The four-metric $g_{\mu\nu}$ is related to the three-metric $\gamma_{ij}$, index-lowered shift $\beta_i$, and lapse $\alpha$ by
# $$
# g_{\mu\nu} = \begin{pmatrix}
# -\alpha^2 + \beta^k \beta_k & \beta_j \\
# \beta_i & \gamma_{ij}
# \end{pmatrix}.
# $$
# This tensor and its inverse have already been built by the u0_smallb_Poynting__Cartesian.py module ([documented here](Tutorial-u0_smallb_Poynting-Cartesian.ipynb)), so we can simply load the module and import the variables.
# $$\label{step3}$$
# Step 1.2: import u0_smallb_Poynting__Cartesian.py to set
# the four metric and its inverse. This module also sets b^2 and u^0.
import u0_smallb_Poynting__Cartesian.u0_smallb_Poynting__Cartesian as u0b
u0b.compute_u0_smallb_Poynting__Cartesian(gammaDD,betaU,alpha,ValenciavU,BU)
betaD = ixp.zerorank1()
for i in range(DIM):
for j in range(DIM):
betaD[i] += gammaDD[i][j] * betaU[j]
# Error check: fixed = to +=
# We will now pull in the four metric and its inverse.
import BSSN.ADMBSSN_tofrom_4metric as AB4m # NRPy+: ADM/BSSN <-> 4-metric conversions
AB4m.g4DD_ito_BSSN_or_ADM("ADM")
g4DD = AB4m.g4DD
AB4m.g4UU_ito_BSSN_or_ADM("ADM")
g4UU = AB4m.g4UU
# Next we compute spatial derivatives of the metric, $\partial_i g_{\mu\nu} = g_{\mu\nu,i}$, written in terms of the three-metric, shift, and lapse. Simply taking the derivative of the expression for $g_{\mu\nu}$ above, we find
# $$
# g_{\mu\nu,l} = \begin{pmatrix}
# -2\alpha \alpha_{,l} + \beta^k_{\ ,l} \beta_k + \beta^k \beta_{k,l} & \beta_{j,l} \\
# \beta_{i,l} & \gamma_{ij,l}
# \end{pmatrix}.
# $$
#
# Notice the derivatives of the shift vector with its indexed lowered, $\beta_{i,j} = \partial_j \beta_i$. This can be easily computed in terms of the given ADMBase quantities $\beta^i$ and $\gamma_{ij}$ via:
# \begin{align}
# \beta_{i,j} &= \partial_j \beta_i \\
# &= \partial_j (\gamma_{ik} \beta^k) \\
# &= \gamma_{ik} \partial_j\beta^k + \beta^k \partial_j \gamma_{ik} \\
# \beta_{i,j} &= \gamma_{ik} \beta^k_{\ ,j} + \beta^k \gamma_{ik,j}.
# \end{align}
#
# Since this expression mixes Greek and Latin indices, we will declare this as a 4 dimensional quantity, but only set the three spatial components of its last index (that is, leaving $l=0$ unset).
#
# So, we will first set
# $$ g_{00,l} = \underbrace{-2\alpha \alpha_{,l}}_{\rm Term\ 1} + \underbrace{\beta^k_{\ ,l} \beta_k}_{\rm Term\ 2} + \underbrace{\beta^k \beta_{k,l}}_{\rm Term\ 3} $$
# Step 1.2, cont'd: Build spatial derivatives of the four metric
# Step 1.2.a: Declare derivatives of grid functions. These will be handled by FD_outputC
alpha_dD = ixp.declarerank1("alpha_dD")
betaU_dD = ixp.declarerank2("betaU_dD","nosym")
gammaDD_dD = ixp.declarerank3("gammaDD_dD","sym01")
# Step 1.2.b: These derivatives will be constructed analytically.
betaDdD = ixp.zerorank2()
g4DDdD = ixp.zerorank3(DIM=4)
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
# \gamma_{ik} \beta^k_{,j} + \beta^k \gamma_{ik,j}
betaDdD[i][j] += gammaDD[i][k] * betaU_dD[k][j] + betaU[k] * gammaDD_dD[i][k][j]
#Error check: changed = to += above
# Step 1.2.c: Set the 00 components
# Step 1.2.c.i: Term 1: -2\alpha \alpha_{,l}
for l in range(DIM):
g4DDdD[0][0][l+1] = -2*alpha*alpha_dD[l]
# Step 1.2.c.ii: Term 2: \beta^k_{\ ,l} \beta_k
for l in range(DIM):
for k in range(DIM):
g4DDdD[0][0][l+1] += betaU_dD[k][l] * betaD[k]
# Step 1.2.c.iii: Term 3: \beta^k \beta_{k,l}
for l in range(DIM):
for k in range(DIM):
g4DDdD[0][0][l+1] += betaU[k] * betaDdD[k][l]
# Now we will contruct the other components of $g_{\mu\nu,l}$. We will first construct
# $$ g_{i0,l} = g_{0i,l} = \beta_{i,l}, $$
# then
# $$ g_{ij,l} = \gamma_{ij,l} $$
# Step 1.2.d: Set the i0 and 0j components
for l in range(DIM):
for i in range(DIM):
# \beta_{i,l}
g4DDdD[i+1][0][l+1] = g4DDdD[0][i+1][l+1] = betaDdD[i][l]
#Step 1.2.e: Set the ij components
for l in range(DIM):
for i in range(DIM):
for j in range(DIM):
# \gamma_{ij,l}
g4DDdD[i+1][j+1][l+1] = gammaDD_dD[i][j][l]
# <a id='step4'></a>
#
# # $T^{\mu\nu}_{\rm EM}$ and its derivatives
#
# Now that the metric and its derivatives are out of the way, let's return to the evolution equation for $\tilde{S}_i$,
# $$
# \partial_t \tilde{S}_i = - \partial_j \left( \alpha \sqrt{\gamma} T^j_{{\rm EM} i} \right) + \frac{1}{2} \alpha \sqrt{\gamma} T^{\mu \nu}_{\rm EM} \partial_i g_{\mu \nu}.
# $$
# We turn our focus now to $T^j_{{\rm EM} i}$ and its derivatives. To this end, we start by computing $T^{\mu \nu}_{\rm EM}$ (from eq. 27 of [Paschalidis & Shapiro's paper on their GRFFE code](https://arxiv.org/pdf/1310.3274.pdf)):
#
# $$\boxed{T^{\mu \nu}_{\rm EM} = b^2 u^{\mu} u^{\nu} + \frac{b^2}{2} g^{\mu \nu} - b^{\mu} b^{\nu}.}$$
#
# Notice that $T^{\mu\nu}_{\rm EM}$ is written in terms of
#
# * $b^\mu$, the 4-component magnetic field vector, related to the comoving magnetic field vector $B^i_{(u)}$
# * $u^\mu$, the 4-velocity
# * $g^{\mu \nu}$, the inverse 4-metric
#
# However, $\texttt{GiRaFFE}$ has access to only the following quantities, requiring in the following sections that we write the above quantities in terms of the following ones:
#
# * $\gamma_{ij}$, the 3-metric
# * $\alpha$, the lapse
# * $\beta^i$, the shift
# * $A_i$, the vector potential
# * $B^i$, the magnetic field (we assume only in the grid interior, not the ghost zones)
# * $\left[\sqrt{\gamma}\Phi\right]$, the zero-component of the vector potential $A_\mu$, times the square root of the determinant of the 3-metric
# * $v_{(n)}^i$, the Valencia 3-velocity
# * $u^0$, the zero-component of the 4-velocity
#
# ## Step 2.0: $u^i$ and $b^i$ and related quantities \[Back to [top](#top)\]
#
# We begin by importing what we can from u0_smallb_Poynting__Cartesian.py. We will need the four-velocity $u^\mu$, which is related to the Valencia 3-velocity $v^i_{(n)}$ used directly by $\texttt{GiRaFFE}$ (see also [Duez, et al, eqs. 53 and 56](https://arxiv.org/pdf/astro-ph/0503420.pdf))
# \begin{align}
# u^i &= u^0 (\alpha v^i_{(n)} - \beta^i), \\
# u_j &= \alpha u^0 \gamma_{ij} v^i_{(n)},
# \end{align}
# where $v^i_{(n)}$ is the Valencia three-velocity. These have already been constructed in terms of the Valencia 3-velocity and other 3+1 ADM quantities by the u0_smallb_Poynting__Cartesian.py module, so we can simply import these variables:
# $$\label{step4}$$
# Step 2.0: u^i, b^i, and related quantities
# Step 2.0.a: import the four-velocity, as written in terms of the Valencia 3-velocity
uD = ixp.zerorank1()
uU = ixp.zerorank1()
u4upperZero = gri.register_gridfunctions("AUX","u4upperZero")
for i in range(DIM):
uD[i] = u0b.uD[i].subs(u0b.u0,u4upperZero)
uU[i] = u0b.uU[i].subs(u0b.u0,u4upperZero)
# We also need the magnetic field 4-vector $b^{\mu}$, which is related to the magnetic field by [eqs. 23, 24, and 31 in Duez, et al](https://arxiv.org/pdf/astro-ph/0503420.pdf):
# \begin{align}
# b^0 &= \frac{1}{\sqrt{4\pi}} B^0_{\rm (u)} = \frac{u_j B^j}{\sqrt{4\pi}\alpha}, \\
# b^i &= \frac{1}{\sqrt{4\pi}} B^i_{\rm (u)} = \frac{B^i + (u_j B^j) u^i}{\sqrt{4\pi}\alpha u^0}, \\
# \end{align}
# where $B^i$ is the variable tracked by the HydroBase thorn in the Einstein Toolkit. Again, these have already been built by the u0_smallb_Poynting__Cartesian.py module, so we can simply import the variables.
# Step 2.0.b: import the small b terms
smallb4U = ixp.zerorank1(DIM=4)
smallb4D = ixp.zerorank1(DIM=4)
for mu in range(4):
smallb4U[mu] = u0b.smallb4U[mu].subs(u0b.u0,u4upperZero)
smallb4D[mu] = u0b.smallb4D[mu].subs(u0b.u0,u4upperZero)
smallb2 = u0b.smallb2etk.subs(u0b.u0,u4upperZero)
# <a id='step5'></a>
#
# ## Step 2.1: Construct all components of the electromagnetic stress-energy tensor $T^{\mu \nu}_{\rm EM}$ \[Back to [top](#top)\]
#
# We now have all the pieces to calculate the stress-energy tensor,
# $$T^{\mu \nu}_{\rm EM} = \underbrace{b^2 u^{\mu} u^{\nu}}_{\rm Term\ 1} +
# \underbrace{\frac{b^2}{2} g^{\mu \nu}}_{\rm Term\ 2}
# - \underbrace{b^{\mu} b^{\nu}}_{\rm Term\ 3}.$$
# Because $u^0$ is a separate variable, we could build the $00$ component separately, then the $\mu0$ and $0\nu$ components, and finally the $\mu\nu$ components. Alternatively, for clarity, we could create a temporary variable $u^\mu=\left( u^0, u^i \right)$
# $$\label{step5}$$
# Step 2.1: Construct the electromagnetic stress-energy tensor
# Step 2.1.a: Set up the four-velocity vector
u4U = ixp.zerorank1(DIM=4)
u4U[0] = u4upperZero
for i in range(DIM):
u4U[i+1] = uU[i]
# Step 2.1.b: Build T4EMUU itself
T4EMUU = ixp.zerorank2(DIM=4)
for mu in range(4):
for nu in range(4):
# Term 1: b^2 u^{\mu} u^{\nu}
T4EMUU[mu][nu] = smallb2*u4U[mu]*u4U[nu]
for mu in range(4):
for nu in range(4):
# Term 2: b^2 / 2 g^{\mu \nu}
T4EMUU[mu][nu] += smallb2*g4UU[mu][nu]/2
for mu in range(4):
for nu in range(4):
# Term 3: -b^{\mu} b^{\nu}
T4EMUU[mu][nu] += -smallb4U[mu]*smallb4U[nu]
#
# # Evolution equation for $\tilde{S}_i$
# <a id='step7'></a>
#
# ## Step 3.0: Construct the evolution equation for $\tilde{S}_i$ \[Back to [top](#top)\]
#
# Finally, we will return our attention to the time evolution equation (from eq. 13 of the [original paper](https://arxiv.org/pdf/1704.00599.pdf)),
# \begin{align}
# \partial_t \tilde{S}_i &= - \partial_j \underbrace{\left( \alpha \sqrt{\gamma} T^j_{{\rm EM} i} \right)}_{\rm SevolParenUD} + \frac{1}{2} \alpha \sqrt{\gamma} T^{\mu \nu}_{\rm EM} \partial_i g_{\mu \nu} \\
# &= - \partial_j{\rm SevolParenUD[i][j]} + \frac{1}{2} \alpha \sqrt{\gamma} T^{\mu \nu}_{\rm EM} \partial_i g_{\mu \nu} .
# \end{align}
# We will first take construct ${\rm SevolParenUD}$, then use its derivatives to construct the evolution equation. Note that
# \begin{align}
# {\rm SevolParenUD[i][j]} &= \alpha \sqrt{\gamma} T^j_{{\rm EM} i} \\
# &= \alpha \sqrt{\gamma} g_{\mu i} T^{\mu j}_{\rm EM}.
# \end{align}
# $$\label{step7}$$
# Step 3.0: Construct the evolution equation for \tilde{S}_i
# Here, we set up the necessary machinery to take FD derivatives of alpha * sqrt(gamma)
global gammaUU,gammadet
gammaUU = ixp.register_gridfunctions_for_single_rank2("AUX","gammaUU","sym01")
gammadet = gri.register_gridfunctions("AUX","gammadet")
gammaUU, gammadet = ixp.symm_matrix_inverter3x3(gammaDD)
alpsqrtgam = alpha*sp.sqrt(gammadet)
global SevolParenUD
SevolParenUD = ixp.register_gridfunctions_for_single_rank2("AUX","SevolParenUD","nosym")
SevolParenUD = ixp.zerorank2()
for i in range(DIM):
for j in range (DIM):
for mu in range(4):
SevolParenUD[j][i] += alpsqrtgam * g4DD[mu][i+1] * T4EMUU[mu][j+1]
SevolParenUD_dD = ixp.declarerank3("SevolParenUD_dD","nosym")
global Stilde_rhsD
Stilde_rhsD = ixp.zerorank1()
# The first term: \alpha \sqrt{\gamma} \partial_j T^j_{{\rm EM} i}
for i in range(DIM):
for j in range(DIM):
Stilde_rhsD[i] += -SevolParenUD_dD[j][i][j]
# The second term: \alpha \sqrt{\gamma} T^{\mu \nu}_{\rm EM} \partial_i g_{\mu \nu} / 2
for i in range(DIM):
for mu in range(4):
for nu in range(4):
Stilde_rhsD[i] += alpsqrtgam * T4EMUU[mu][nu] * g4DDdD[mu][nu][i+1] / 2
# # Evolution equations for $A_i$ and $\Phi$
# <a id='step8'></a>
#
# ## Step 4.0: Construct the evolution equations for $A_i$ and $[\sqrt{\gamma}\Phi]$ \[Back to [top](#top)\]
#
# We will also need to evolve the vector potential $A_i$. This evolution is given as eq. 17 in the [$\texttt{GiRaFFE}$](https://arxiv.org/pdf/1704.00599.pdf) paper:
# $$\boxed{\partial_t A_i = \epsilon_{ijk} v^j B^k - \partial_i (\underbrace{\alpha \Phi - \beta^j A_j}_{\rm AevolParen}),}$$
# where $\epsilon_{ijk} = [ijk] \sqrt{\gamma}$ is the antisymmetric Levi-Civita tensor, the drift velocity $v^i = u^i/u^0$, $\gamma$ is the determinant of the three metric, $B^k$ is the magnetic field, $\alpha$ is the lapse, and $\beta$ is the shift.
# The scalar electric potential $\Phi$ is also evolved by eq. 19:
# $$\boxed{\partial_t [\sqrt{\gamma} \Phi] = -\partial_j (\underbrace{\alpha\sqrt{\gamma} \gamma^{ij} A_i - \beta^j [\sqrt{\gamma} \Phi]}_{\rm PevolParenU[j]}) - \xi \alpha [\sqrt{\gamma} \Phi],}$$
# with $\xi$ chosen as a damping factor.
#
# ### Step 4.0.a: Construct some useful auxiliary gridfunctions for the other evolution equations
#
# After declaring a some needed quantities, we will also define the parenthetical terms (underbrace above) that we need to take derivatives of. That way, we can take finite-difference derivatives easily. Note that the above equations incorporate the fact that $\gamma^{ij}$ is the appropriate raising operator for $A_i$: $A^j = \gamma^{ij} A_i$. This is correct since $n_\mu A^\mu = 0$, where $n_\mu$ is a normal to the hypersurface, so $A^0=0$ (according to Sec. II, subsection C of [the "Improved EM gauge condition" paper of Etienne *et al*](https://arxiv.org/pdf/1110.4633.pdf)).
# $$\label{step8}$$
# Step 4.0: Construct the evolution equations for A_i and sqrt(gamma)Phi
# Step 4.0.a: Construct some useful auxiliary gridfunctions for the other evolution equations
xi = par.Cparameters("REAL",thismodule,"xi", 0.1) # The (dimensionful) Lorenz damping factor. Recommendation: set to ~1.5/max(delta t).
# Define sqrt(gamma)Phi as psi6Phi
psi6Phi = gri.register_gridfunctions("EVOL","psi6Phi")
Phi = psi6Phi / sp.sqrt(gammadet)
# We'll define a few extra gridfunctions to avoid complicated derivatives
global AevolParen,PevolParenU
AevolParen = gri.register_gridfunctions("AUX","AevolParen")
PevolParenU = ixp.register_gridfunctions_for_single_rank1("AUX","PevolParenU")
# {\rm AevolParen} = \alpha \Phi - \beta^j A_j
AevolParen = alpha*Phi
for j in range(DIM):
AevolParen += -betaU[j] * AD[j]
# {\rm PevolParenU[j]} = \alpha\sqrt{\gamma} \gamma^{ij} A_i - \beta^j [\sqrt{\gamma} \Phi]
for j in range(DIM):
PevolParenU[j] = -betaU[j] * psi6Phi
for i in range(DIM):
PevolParenU[j] += alpsqrtgam * gammaUU[i][j] * AD[i]
AevolParen_dD = ixp.declarerank1("AevolParen_dD")
PevolParenU_dD = ixp.declarerank2("PevolParenU_dD","nosym")
# ### Step 4.0.b: Complete the construction of the evolution equations for $A_i$ and $[\sqrt{\gamma}\Phi]$
#
# Now to set the evolution equations ([eqs. 17 and 19](https://arxiv.org/pdf/1704.00599.pdf)), recalling that the drift velocity $v^i = u^i/u^0$:
# \begin{align}
# \partial_t A_i &= \epsilon_{ijk} v^j B^k - \partial_i (\alpha \Phi - \beta^j A_j) \\
# &= \epsilon_{ijk} \frac{u^j}{u^0} B^k - {\rm AevolParen\_dD[i]} \\
# \partial_t [\sqrt{\gamma} \Phi] &= -\partial_j \left(\left(\alpha\sqrt{\gamma}\right)A^j - \beta^j [\sqrt{\gamma} \Phi]\right) - \xi \alpha [\sqrt{\gamma} \Phi] \\
# &= -{\rm PevolParenU\_dD[j][j]} - \xi \alpha [\sqrt{\gamma} \Phi]. \\
# \end{align}
# Step 4.0.b: Construct the actual evolution equations for A_i and sqrt(gamma)Phi
global A_rhsD,psi6Phi_rhs
A_rhsD = ixp.zerorank1()
psi6Phi_rhs = sp.sympify(0)
# We already have a handy function to define the Levi-Civita symbol in WeylScalars
import WeylScal4NRPy.WeylScalars_Cartesian as weyl
# Initialize the Levi-Civita tensor by setting it equal to the Levi-Civita symbol
LeviCivitaSymbolDDD = weyl.define_LeviCivitaSymbol_rank3()
LeviCivitaTensorDDD = ixp.zerorank3()
#LeviCivitaTensorUUU = ixp.zerorank3()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
LeviCivitaTensorDDD[i][j][k] = LeviCivitaSymbolDDD[i][j][k] * sp.sqrt(gammadet)
#LeviCivitaTensorUUU[i][j][k] = LeviCivitaSymbolDDD[i][j][k] / sp.sqrt(gammadet)
for i in range(DIM):
A_rhsD[i] = -AevolParen_dD[i]
for j in range(DIM):
for k in range(DIM):
A_rhsD[i] += LeviCivitaTensorDDD[i][j][k]*(uU[j]/u4upperZero)*BU[k]
psi6Phi_rhs = -xi*alpha*psi6Phi
for j in range(DIM):
psi6Phi_rhs += -PevolParenU_dD[j][j]
def GiRaFFE_Higher_Order():
#Step 1.0: Set the spatial dimension parameter to 3.
par.set_parval_from_str("grid::DIM", 3)
DIM = par.parval_from_str("grid::DIM")
# Step 1.1: Set the finite differencing order to 4.
#par.set_parval_from_str("finite_difference::FD_CENTDERIVS_ORDER", 4)
thismodule = "GiRaFFE_NRPy"
# M_PI will allow the C code to substitute the correct value
M_PI = par.Cparameters("#define", thismodule, "M_PI", "")
# ADMBase defines the 4-metric in terms of the 3+1 spacetime metric quantities gamma_{ij}, beta^i, and alpha
gammaDD = ixp.register_gridfunctions_for_single_rank2("AUX",
"gammaDD",
"sym01",
DIM=3)
betaU = ixp.register_gridfunctions_for_single_rank1("AUX", "betaU", DIM=3)
alpha = gri.register_gridfunctions("AUX", "alpha")
# GiRaFFE uses the Valencia 3-velocity and A_i, which are defined in the initial data module(GiRaFFEfood)
ValenciavU = ixp.register_gridfunctions_for_single_rank1("AUX",
"ValenciavU",
DIM=3)
AD = ixp.register_gridfunctions_for_single_rank1("EVOL", "AD", DIM=3)
# B^i must be computed at each timestep within GiRaFFE so that the Valencia 3-velocity can be evaluated
BU = ixp.register_gridfunctions_for_single_rank1("AUX", "BU", DIM=3)
# <a id='step3'></a>
#
# ## Step 1.2: Build the four metric $g_{\mu\nu}$, its inverse $g^{\mu\nu}$ and spatial derivatives $g_{\mu\nu,i}$ from ADM 3+1 quantities $\gamma_{ij}$, $\beta^i$, and $\alpha$
#
# $$\label{step3}$$
# \[Back to [top](#top)\]
#
# Notice that the time evolution equation for $\tilde{S}_i$
# $$
# \partial_t \tilde{S}_i = - \partial_j \left( \alpha \sqrt{\gamma} T^j_{{\rm EM} i} \right) + \frac{1}{2} \alpha \sqrt{\gamma} T^{\mu \nu}_{\rm EM} \partial_i g_{\mu \nu}
# $$
# contains $\partial_i g_{\mu \nu} = g_{\mu\nu,i}$. We will now focus on evaluating this term.
#
# The four-metric $g_{\mu\nu}$ is related to the three-metric $\gamma_{ij}$, index-lowered shift $\beta_i$, and lapse $\alpha$ by
# $$
# g_{\mu\nu} = \begin{pmatrix}
# -\alpha^2 + \beta^k \beta_k & \beta_j \\
# \beta_i & \gamma_{ij}
# \end{pmatrix}.
# $$
# This tensor and its inverse have already been built by the u0_smallb_Poynting__Cartesian.py module ([documented here](Tutorial-u0_smallb_Poynting-Cartesian.ipynb)), so we can simply load the module and import the variables.
# Step 1.2: import u0_smallb_Poynting__Cartesian.py to set
# the four metric and its inverse. This module also sets b^2 and u^0.
import u0_smallb_Poynting__Cartesian.u0_smallb_Poynting__Cartesian as u0b
u0b.compute_u0_smallb_Poynting__Cartesian(gammaDD, betaU, alpha,
ValenciavU, BU)
betaD = ixp.zerorank1()
for i in range(DIM):
for j in range(DIM):
betaD[i] += gammaDD[i][j] * betaU[j]
# We will now pull in the four metric and its inverse.
import BSSN.ADMBSSN_tofrom_4metric as AB4m # NRPy+: ADM/BSSN <-> 4-metric conversions
AB4m.g4DD_ito_BSSN_or_ADM("ADM")
g4DD = AB4m.g4DD
AB4m.g4UU_ito_BSSN_or_ADM("ADM")
g4UU = AB4m.g4UU
# Next we compute spatial derivatives of the metric, $\partial_i g_{\mu\nu} = g_{\mu\nu,i}$, written in terms of the three-metric, shift, and lapse. Simply taking the derivative of the expression for $g_{\mu\nu}$ above, we find
# $$
# g_{\mu\nu,l} = \begin{pmatrix}
# -2\alpha \alpha_{,l} + \beta^k_{\ ,l} \beta_k + \beta^k \beta_{k,l} & \beta_{i,l} \\
# \beta_{j,l} & \gamma_{ij,l}
# \end{pmatrix}.
# $$
#
# Notice the derivatives of the shift vector with its indexed lowered, $\beta_{i,j} = \partial_j \beta_i$. This can be easily computed in terms of the given ADMBase quantities $\beta^i$ and $\gamma_{ij}$ via:
# \begin{align}
# \beta_{i,j} &= \partial_j \beta_i \\
# &= \partial_j (\gamma_{ik} \beta^k) \\
# &= \gamma_{ik} \partial_j\beta^k + \beta^k \partial_j \gamma_{ik} \\
# \beta_{i,j} &= \gamma_{ik} \beta^k_{\ ,j} + \beta^k \gamma_{ik,j}.
# \end{align}
#
# Since this expression mixes Greek and Latin indices, we will need to store the expressions for each of the three spatial derivatives as separate variables.
#
# So, we will first set
# $$ g_{00,l} = \underbrace{-2\alpha \alpha_{,l}}_{\rm Term\ 1} + \underbrace{\beta^k_{\ ,l} \beta_k}_{\rm Term\ 2} + \underbrace{\beta^k \beta_{k,l}}_{\rm Term\ 3} $$
# Step 1.2, cont'd: Build spatial derivatives of the four metric
# Step 1.2.a: Declare derivatives of grid functions. These will be handled by FD_outputC
alpha_dD = ixp.declarerank1("alpha_dD")
betaU_dD = ixp.declarerank2("betaU_dD", "nosym")
gammaDD_dD = ixp.declarerank3("gammaDD_dD", "sym01")
# Step 1.2.b: These derivatives will be constructed analytically.
betaDdD = ixp.zerorank2()
g4DDdD = ixp.zerorank3(DIM=4)
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
# \gamma_{ik} \beta^k_{,j} + \beta^k \gamma_{ik,j}
betaDdD[i][j] += gammaDD[i][k] * betaU_dD[k][j] + betaU[
k] * gammaDD_dD[i][k][j]
# Step 1.2.c: Set the 00 components
# Step 1.2.c.i: Term 1: -2\alpha \alpha_{,l}
for l in range(DIM):
g4DDdD[0][0][l + 1] = -2 * alpha * alpha_dD[l]
# Step 1.2.c.ii: Term 2: \beta^k_{\ ,l} \beta_k
for l in range(DIM):
for k in range(DIM):
g4DDdD[0][0][l + 1] += betaU_dD[k][l] * betaD[k]
# Step 1.2.c.iii: Term 3: \beta^k \beta_{k,l}
for l in range(DIM):
for k in range(DIM):
g4DDdD[0][0][l + 1] += betaU[k] * betaDdD[k][l]
# Now we will contruct the other components of $g_{\mu\nu,l}$. We will first construct
# $$ g_{i0,l} = g_{0i,l} = \beta_{i,l}, $$
# then
# $$ g_{ij,l} = \gamma_{ij,l} $$
# Step 1.2.d: Set the i0 and 0j components
for l in range(DIM):
for i in range(DIM):
# \beta_{i,l}
g4DDdD[i + 1][0][l + 1] = g4DDdD[0][i + 1][l + 1] = betaDdD[i][l]
#Step 1.2.e: Set the ij components
for l in range(DIM):
for i in range(DIM):
for j in range(DIM):
# \gamma_{ij,l}
g4DDdD[i + 1][j + 1][l + 1] = gammaDD_dD[i][j][l]
# <a id='step4'></a>
#
# # $T^{\mu\nu}_{\rm EM}$ and its derivatives
#
# Now that the metric and its derivatives are out of the way, let's return to the evolution equation for $\tilde{S}_i$,
# $$
# \partial_t \tilde{S}_i = - \partial_j \left( \alpha \sqrt{\gamma} T^j_{{\rm EM} i} \right) + \frac{1}{2} \alpha \sqrt{\gamma} T^{\mu \nu}_{\rm EM} \partial_i g_{\mu \nu}.
# $$
# We turn our focus now to $T^j_{{\rm EM} i}$ and its derivatives. To this end, we start by computing $T^{\mu \nu}_{\rm EM}$ (from eq. 27 of [Paschalidis & Shapiro's paper on their GRFFE code](https://arxiv.org/pdf/1310.3274.pdf)):
#
# $$\boxed{T^{\mu \nu}_{\rm EM} = b^2 u^{\mu} u^{\nu} + \frac{b^2}{2} g^{\mu \nu} - b^{\mu} b^{\nu}.}$$
#
# Notice that $T^{\mu\nu}_{\rm EM}$ is written in terms of
#
# * $b^\mu$, the 4-component magnetic field vector, related to the comoving magnetic field vector $B^i_{(u)}$
# * $u^\mu$, the 4-velocity
# * $g^{\mu \nu}$, the inverse 4-metric
#
# However, $\texttt{GiRaFFE}$ has access to only the following quantities, requiring in the following sections that we write the above quantities in terms of the following ones:
#
# * $\gamma_{ij}$, the 3-metric
# * $\alpha$, the lapse
# * $\beta^i$, the shift
# * $A_i$, the vector potential
# * $B^i$, the magnetic field (we assume only in the grid interior, not the ghost zones)
# * $\left[\sqrt{\gamma}\Phi\right]$, the zero-component of the vector potential $A_\mu$, times the square root of the determinant of the 3-metric
# * $v_{(n)}^i$, the Valencia 3-velocity
# * $u^0$, the zero-component of the 4-velocity
#
# ## Step 2.0: $u^i$ and $b^i$ and related quantities
# $$\label{step4}$$
# \[Back to [top](#top)\]
#
# We begin by importing what we can from u0_smallb_Poynting__Cartesian.py. We will need the four-velocity $u^\mu$, which is related to the Valencia 3-velocity $v^i_{(n)}$ used directly by $\texttt{GiRaFFE}$ (see also [Duez, et al, eqs. 53 and 56](https://arxiv.org/pdf/astro-ph/0503420.pdf))
# \begin{align}
# u^i &= u^0 (\alpha v^i_{(n)} - \beta^i), \\
# u_j &= \alpha u^0 \gamma_{ij} v^i_{(n)},
# \end{align}
# and $v^i_{(n)}$ is the Valencia three-velocity. These have already been constructed in terms of the Valencia 3-velocity and other 3+1 ADM quantities by the u0_smallb_Poynting__Cartesian.py module, so we can simply import these variables:
# Step 2.0: u^i, b^i, and related quantities
# Step 2.0.a: import the four-velocity, as written in terms of the Valencia 3-velocity
global uD, uU
uD = ixp.register_gridfunctions_for_single_rank1("AUX", "uD")
uU = ixp.register_gridfunctions_for_single_rank1("AUX", "uU")
u4upperZero = gri.register_gridfunctions("AUX", "u4upperZero")
for i in range(DIM):
uD[i] = u0b.uD[i].subs(u0b.u0, u4upperZero)
uU[i] = u0b.uU[i].subs(u0b.u0, u4upperZero)
# We also need the magnetic field 4-vector $b^{\mu}$, which is related to the magnetic field by [eqs. 23, 24, and 31 in Duez, et al](https://arxiv.org/pdf/astro-ph/0503420.pdf):
# \begin{align}
# b^0 &= \frac{1}{\sqrt{4\pi}} B^0_{\rm (u)} = \frac{u_j B^j}{\sqrt{4\pi}\alpha}, \\
# b^i &= \frac{1}{\sqrt{4\pi}} B^i_{\rm (u)} = \frac{B^i + (u_j B^j) u^i}{\sqrt{4\pi}\alpha u^0}, \\
# \end{align}
# where $B^i$ is the variable tracked by the HydroBase thorn in the Einstein Toolkit. Again, these have already been built by the u0_smallb_Poynting__Cartesian.py module, so we can simply import the variables.
# Step 2.0.b: import the small b terms
smallb4U = ixp.zerorank1(DIM=4)
smallb4D = ixp.zerorank1(DIM=4)
for mu in range(4):
smallb4U[mu] = u0b.smallb4U[mu].subs(u0b.u0, u4upperZero)
smallb4D[mu] = u0b.smallb4D[mu].subs(u0b.u0, u4upperZero)
smallb2 = u0b.smallb2etk.subs(u0b.u0, u4upperZero)
# <a id='step5'></a>
#
# ## Step 2.1: Construct all components of the electromagnetic stress-energy tensor $T^{\mu \nu}_{\rm EM}$
# $$\label{step5}$$
#
# \[Back to [top](#top)\]
#
# We now have all the pieces to calculate the stress-energy tensor,
# $$T^{\mu \nu}_{\rm EM} = \underbrace{b^2 u^{\mu} u^{\nu}}_{\rm Term\ 1} +
# \underbrace{\frac{b^2}{2} g^{\mu \nu}}_{\rm Term\ 2}
# - \underbrace{b^{\mu} b^{\nu}}_{\rm Term\ 3}.$$
# Because $u^0$ is a separate variable, we could build the $00$ component separately, then the $\mu0$ and $0\nu$ components, and finally the $\mu\nu$ components. Alternatively, for clarity, we could create a temporary variable $u^\mu=\left( u^0, u^i \right)$
# Step 2.1: Construct the electromagnetic stress-energy tensor
# Step 2.1.a: Set up the four-velocity vector
u4U = ixp.zerorank1(DIM=4)
u4U[0] = u4upperZero
for i in range(DIM):
u4U[i + 1] = uU[i]
# Step 2.1.b: Build T4EMUU itself
T4EMUU = ixp.zerorank2(DIM=4)
for mu in range(4):
for nu in range(4):
# Term 1: b^2 u^{\mu} u^{\nu}
T4EMUU[mu][nu] = smallb2 * u4U[mu] * u4U[nu]
for mu in range(4):
for nu in range(4):
# Term 2: b^2 / 2 g^{\mu \nu}
T4EMUU[mu][nu] += smallb2 * g4UU[mu][nu] / 2
for mu in range(4):
for nu in range(4):
# Term 3: -b^{\mu} b^{\nu}
T4EMUU[mu][nu] += -smallb4U[mu] * smallb4U[nu]
# <a id='step6'></a>
#
# # Step 2.2: Derivatives of the electromagnetic stress-energy tensor
# $$\label{step6}$$
#
# \[Back to [top](#top)\]
#
# If we look at the evolution equation, we see that we will need spatial derivatives of $T^{\mu\nu}_{\rm EM}$. When confronted with derivatives of complicated expressions, it is generally convenient to declare those expressions as gridfunctions themselves, allowing NRPy+ to take finite-difference derivatives of the expressions. This can even reduce the truncation error associated with the finite differences, because the alternative is to use a function of several finite-difference derivatives, allowing more error to accumulate than the extra gridfunction will introduce. While we will use that technique for some of the subexpressions of $T^{\mu\nu}_{\rm EM}$, we don't want to rely on it for the whole expression; doing so would require us to take the derivative of the magnetic field $B^i$, which is itself found by finite-differencing the vector potential $A_i$. Thus $B^i$ cannot be *consistently* defined in ghost zones. To potentially reduce numerical errors induced by inconsistent finite differencing, we will differentiate $T^{\mu\nu}_{\rm EM}$ term-by-term so that finite-difference derivatives of $A_i$ appear.
#
# We will now now take these spatial derivatives of $T^{\mu\nu}_{\rm EM}$, applying the chain rule until it is only in terms of basic gridfunctions and their derivatives: $\alpha$, $\beta^i$, $\gamma_{ij}$, $A_i$, and the four-velocity $u^i$. Along the way, we will also set up useful temporary variables representing the steps of the chain rule. (Notably, *all* of these quantities will be written in terms of $A_i$ and its derivatives):
#
# * $B^i$ (already computed in terms of $A_k$, via $B^i = \epsilon^{ijk} \partial_j A_k$),
# * $B^i_{,l}$,
# * $b^i$ and $b_i$ (already computed),
# * $b^i_{,k}$,
# * $b^2$ (already computed),
# * and $\left(b^2\right)_{,j}$.
#
# (The variables not already computed will not be seen by the ETK, as they are written in terms of $A_i$ and its derivatives; they simply help to organize the NRPy+ code.)
#
# So then,
# \begin{align}
# \partial_j T^{j}_{{\rm EM} i} &= \partial_j (g_{\mu i} T^{\mu j}_{\rm EM}) \\
# &= \partial_j \left[g_{\mu i} \left(b^2 u^j u^\mu + \frac{b^2}{2} g^{j\mu} - b^j b^\mu\right)\right] \\
# &= \underbrace{g_{\mu i,j} T^{\mu j}_{\rm EM}}_{\rm Term\ A} + g_{\mu i} \left( \underbrace{\partial_j \left(b^2 u^j u^\mu \right)}_{\rm Term\ B} + \underbrace{\partial_j \left(\frac{b^2}{2} g^{j\mu}\right)}_{\rm Term\ C} - \underbrace{\partial_j \left(b^j b^k\right)}_{\rm Term\ D} \right) \\
# \end{align}
# Following the product and chain rules for each term, we find that
# \begin{align}
# {\rm Term\ B} &= \partial_j (b^2 u^j u^\mu) \\
# &= \partial_j b^2 u^j u^\mu + b^2 \partial_j u^j u^\mu + b^2 u^j \partial_j u^\mu \\
# &= \underbrace{\left(b^2\right)_{,j} u^j u^\mu + b^2 u^j_{,j} u^\mu + b^2 u^j u^{\mu}_{,j}}_{\rm To\ Term\ 2\ below} \\
# {\rm Term\ C} &= \partial_j \left(\frac{b^2}{2} g^{j\mu}\right) \\
# &= \frac{1}{2} \left( \partial_j b^2 g^{j\mu} + b^2 \partial_j g^{j\mu} \right) \\
# &= \underbrace{\frac{1}{2} \left(b^2\right)_{,j} g^{j\mu} + \frac{b^2}{2} g^{j\mu}_{\ ,j}}_{\rm To\ Term\ 3\ below} \\
# {\rm Term\ D} &= \partial_j (b^j b^\mu) \\
# &= \underbrace{b^j_{,j} b^\mu + b^j b^\mu_{,j}}_{\rm To\ Term\ 2\ below}\\
# \end{align}
#
# So,
# \begin{align}
# \partial_j T^{j}_{{\rm EM} i} &= g_{\mu i,j} T^{\mu j}_{\rm EM} \\
# &+ g_{\mu i} \left(\left(b^2\right)_{,j} u^j u^\mu +b^2 u^j_{,j} u^\mu + b^2 u^j u^{\mu}_{,j} + \frac{1}{2}\left(b^2\right)_{,j} g^{j\mu} + \frac{b^2}{2} g^{j\mu}_{\ ,j} + b^j_{,j} b^\mu + b^j b^\mu_{,j}\right);
# \end{align}
# We will rearrange this once more, collecting the $b^2$ terms together, noting that Term A will become Term 1:
# \begin{align}
# \partial_j T^{j}_{{\rm EM} i} =& \
# \underbrace{g_{\mu i,j} T^{\mu j}_{\rm EM}}_{\rm Term\ 1} \\
# & + \underbrace{g_{\mu i} \left( b^2 u^j_{,j} u^\mu + b^2 u^j u^\mu_{,j} + \frac{b^2}{2} g^{j\mu}_{\ ,j} + b^j_{,j} b^\mu + b^j b^\mu_{,j} \right)}_{\rm Term\ 2} \\
# & + \underbrace{g_{\mu i} \left( \left(b^2\right)_{,j} u^j u^\mu + \frac{1}{2} \left(b^2\right)_{,j} g^{j\mu} \right).}_{\rm Term\ 3} \\
# \end{align}
#
# <a id='table2'></a>
#
# **List of Derivatives**
# $$\label{table2}$$
#
# Note that this is in terms of the derivatives of several other quantities:
#
# * [Step 2.2.a](#capitalBideriv): $B^i_{,l}$: Since $b^i$ is itself a function of $B^i$, we will first need the derivatives $B^i_{,l}$ in terms of the evolved quantity $A_i$ (the vector potential).
# * [Step 2.2.b](#bideriv): $b^i_{,k}$: Once we have $B^i_{,l}$ we can evaluate derivatives of $b^i$, $b^i_{,k}$
# * [Step 2.2.c](#b2deriv): The derivative of $b^2 = g_{\mu\nu} b^\mu b^\nu$, $\left(b^2\right)_{,j}$
# * [Step 2.2.d](#gupijderiv): Derivatives of $g^{\mu\nu}$, $g^{\mu\nu}_{\ ,k}$
# * [Step 2.2.e](#alltogether): Putting it together: $\partial_j T^{j}_{{\rm EM} i}$
# * [Step 2.2.e.i](#alltogether1): Putting it together: Term 1
# * [Step 2.2.e.ii](#alltogether2): Putting it together: Term 2
# * [Step 2.2.e.iii](#alltogether3): Putting it together: Term 3
# <a id='capitalBideriv'></a>
#
# ## Step 2.2.a: Derivatives of $B^i$
#
# $$\label{capitalbideriv}$$
#
# \[Back to [List of Derivatives](#table2)\]
#
# First, we will build the derivatives of the magnetic field. Since $b^i$ is a function of $B^i$, we will start from the definition of $B^i$ in terms of $A_i$, $B^i = \frac{[ijk]}{\sqrt{\gamma}} \partial_j A_k$. We will first apply the product rule, noting that the symbol $[ijk]$ consists purely of the integers $-1, 0, 1$ and thus can be treated as a constant in this process.
# \begin{align}
# B^i_{,l} &= \partial_l \left( \frac{[ijk]}{\sqrt{\gamma}} \partial_j A_k \right) \\
# &= [ijk] \partial_l \left( \frac{1}{\sqrt{\gamma}}\right) \partial_j A_k + \frac{[ijk]}{\sqrt{\gamma}} \partial_l \partial_j A_k \\
# &= [ijk]\left(-\frac{\gamma_{,l}}{2\gamma^{3/2}}\right) \partial_j A_k + \frac{[ijk]}{\sqrt{\gamma}} \partial_l \partial_j A_k \\
# \end{align}
# Now, we will substitute back in for the definition of the Levi-Civita tensor: $\epsilon^{ijk} = [ijk] / \sqrt{\gamma}$. Then we will substitute the magnetic field $B^i$ back in.
# \begin{align}
# B^i_{,l} &= -\frac{\gamma_{,l}}{2\gamma} \epsilon^{ijk} \partial_j A_k + \epsilon^{ijk} \partial_l \partial_j A_k \\
# &= -\frac{\gamma_{,l}}{2\gamma} B^i + \epsilon^{ijk} A_{k,jl}, \\
# \end{align}
#
# Thus, the expression we are left with for the derivatives of the magnetic field is:
# \begin{align}
# B^i_{,l} &= \underbrace{-\frac{\gamma_{,l}}{2\gamma} B^i}_{\rm Term\ 1} + \underbrace{\epsilon^{ijk} A_{k,jl}}_{\rm Term\ 2}, \\
# \end{align}
# where $\epsilon^{ijk} = [ijk] / \sqrt{\gamma}$ is the antisymmetric Levi-Civita tensor and $\gamma$ is the determinant of the three-metric.
#
# Step 2.2: Derivatives of the electromagnetic stress-energy tensor
# We already have a handy function to define the Levi-Civita symbol in WeylScalars
import WeylScal4NRPy.WeylScalars_Cartesian as weyl
# Initialize the Levi-Civita tensor by setting it equal to the Levi-Civita symbol
LeviCivitaSymbolDDD = weyl.define_LeviCivitaSymbol_rank3()
LeviCivitaTensorDDD = ixp.zerorank3()
LeviCivitaTensorUUU = ixp.zerorank3()
global gammaUU, gammadet
gammaUU = ixp.register_gridfunctions_for_single_rank2(
"AUX", "gammaUU", "sym01")
gammadet = gri.register_gridfunctions("AUX", "gammadet")
gammaUU, gammadet = ixp.symm_matrix_inverter3x3(gammaDD)
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
LeviCivitaTensorDDD[i][j][
k] = LeviCivitaSymbolDDD[i][j][k] * sp.sqrt(gammadet)
LeviCivitaTensorUUU[i][j][
k] = LeviCivitaSymbolDDD[i][j][k] / sp.sqrt(gammadet)
AD_dD = ixp.declarerank2("AD_dD", "nosym")
# Step 2.2.a: Construct the derivatives of the magnetic field.
gammadet_dD = ixp.declarerank1("gammadet_dD")
AD_dDD = ixp.declarerank3("AD_dDD", "sym12")
# The other partial derivatives of B^i
BUdD = ixp.zerorank2()
for i in range(DIM):
for l in range(DIM):
# Term 1: -\gamma_{,l} / (2\gamma) B^i
BUdD[i][l] = -gammadet_dD[l] * BU[i] / (2 * gammadet)
for i in range(DIM):
for l in range(DIM):
for j in range(DIM):
for k in range(DIM):
# Term 2: \epsilon^{ijk} A_{k,jl}
BUdD[i][
l] += LeviCivitaTensorUUU[i][j][k] * AD_dDD[k][j][l]
# <a id='bideriv'></a>
#
# ## Step 2.2.b: Derivatives of $b^i$
# $$\label{bideriv}$$
#
# \[Back to [List of Derivatives](#table2)\]
#
# Now, we will code the derivatives of the spatial components of $b^{\mu}$, $b^i$:
# $$
# b^i_{,k} = \frac{1}{\sqrt{4 \pi}} \frac{\left(\alpha u^0\right) \left(B^i_{,k} + u_{j,k} B^j u^i + u_j B^j_{,k} u^i + u_j B^j u^i_{,k}\right) - \left(B^i + (u_j B^j) u^i\right) \partial_k \left(\alpha u^0\right)}{\left(\alpha u^0\right)^2}.
# $$
#
# We should note that while $b^\mu$ is a four-vector (and the code reflects this: $\text{smallb4U}$ and $\text{smallb4U}$ have $\text{DIM=4}$), we only need the spatial components. We will only focus on the spatial components for the moment.
#
#
# Let's go into a little more detail on where this comes from. We start from the definition $$b^i = \frac{B^i + (u_j B^j) u^i}{\sqrt{4\pi}\alpha u^0};$$ we then apply the quotient rule:
# \begin{align}
# b^i_{,k} &= \frac{\left(\sqrt{4\pi}\alpha u^0\right) \partial_k \left(B^i + (u_j B^j) u^i\right) - \left(B^i + (u_j B^j) u^i\right) \partial_k \left(\sqrt{4\pi}\alpha u^0\right)}{\left(\sqrt{4\pi}\alpha u^0\right)^2} \\
# &= \frac{1}{\sqrt{4 \pi}} \frac{\left(\alpha u^0\right) \partial_k \left(B^i + (u_j B^j) u^i\right) - \left(B^i + (u_j B^j) u^i\right) \partial_k \left(\alpha u^0\right)}{\left(\alpha u^0\right)^2} \\
# \end{align}
# Note that $\left( \alpha u^0 \right)$ is being used as its own gridfunction, so $\partial_k \left(a u^0\right)$ will be finite-differenced by NRPy+ directly. We will also apply the product rule to the term $\partial_k \left(B^i + (u_j B^j) u^i\right) = B^i_{,k} + u_{j,k} B^j u^i + u_j B^j_{,k} u^i + u_j B^j u^i_{,k}$. So,
# $$ b^i_{,k} = \frac{1}{\sqrt{4 \pi}} \frac{\left(\alpha u^0\right) \left(B^i_{,k} + u_{j,k} B^j u^i + u_j B^j_{,k} u^i + u_j B^j u^i_{,k}\right) - \left(B^i + (u_j B^j) u^i\right) \partial_k \left(\alpha u^0\right)}{\left(\alpha u^0\right)^2}. $$
#
# It will be easier to code this up if we rearrange these terms to group together the terms that involve contractions over $j$. Doing that, we find
# $$
# b^i_{,k} = \frac{\overbrace{\alpha u^0 B^i_{,k} - B^i \partial_k (\alpha u^0)}^{\rm Term\ Num1} + \overbrace{\left( \alpha u^0 \right) \left( u_{j,k} B^j u^i + u_j B^j_{,k} u^i + u_j B^j u^i_{,k} \right)}^{\rm Term\ Num2.a} - \overbrace{\left( u_j B^j u^i \right) \partial_k \left( \alpha u^0 \right) }^{\rm Term\ Num2.b}}{\underbrace{\sqrt{4 \pi} \left( \alpha u^0 \right)^2}_{\rm Term\ Denom}}.
# $$
global u0alpha
u0alpha = gri.register_gridfunctions("AUX", "u0alpha")
u0alpha = alpha * u4upperZero
u0alpha_dD = ixp.declarerank1("u0alpha_dD")
uU_dD = ixp.declarerank2("uU_dD", "nosym")
uD_dD = ixp.declarerank2("uD_dD", "nosym")
# Step 2.2.b: Construct derivatives of the small b vector
# smallbUdD represents the derivative of smallb4U
smallbUdD = ixp.zerorank2()
for i in range(DIM):
for k in range(DIM):
# Term Num1: \alpha u^0 B^i_{,k} - B^i \partial_k (\alpha u^0)
smallbUdD[i][k] += u0alpha * BUdD[i][k] - BU[i] * u0alpha_dD[k]
for i in range(DIM):
for k in range(DIM):
for j in range(DIM):
# Term Num2.a: terms that require contractions over k, and thus an extra loop.
# ( \alpha u^0 ) ( u_{j,k} B^j u^i
# + u_j B^j_{,k} u^i
# + u_j B^j u^i_{,k} )
smallbUdD[i][k] += u0alpha * (uD_dD[j][k] * BU[j] * uU[i] +
uD[j] * BUdD[j][k] * uU[i] +
uD[j] * BU[j] * uU_dD[i][k])
for i in range(DIM):
for k in range(DIM):
for j in range(DIM):
#Term 2.b (More contractions over k): ( u_j B^j u^i ) ( \alpha u^0 ),k
smallbUdD[i][k] += -(uD[j] * BU[j] * uU[i]) * u0alpha_dD[k]
for i in range(DIM):
for k in range(DIM):
# Term Denom: Divide the numerator by sqrt(4 pi) * (alpha u^0)^2
smallbUdD[i][k] /= sp.sqrt(4 * M_PI) * u0alpha * u0alpha
# <a id='b2deriv'></a>
#
# ## Step 2.2.c: Derivative of $b^2$
# $$\label{b2deriv}$$
#
# \[Back to [List of Derivatives](#table2)\]
#
# Here, we will take the derivative of $b^2 = g_{\mu\nu} b^\mu b^\nu$. Using the product rule,
# \begin{align}
# \left(b^2\right)_{,j} &= \partial_j \left( g_{\mu\nu} b^\mu b^\nu \right) \\
# &= g_{\mu\nu,j} b^\mu b^\nu + g_{\mu\nu} b^\mu_{,j} b^\nu + g_{\mu\nu} b^\mu b^\nu_{,j} \\
# &= g_{\mu\nu,j} b^\mu b^\nu + 2 g_{\mu\nu} b^\mu_{,j} b^\nu.
# \end{align}
# We have already defined the spatial derivatives of the four-metric $g_{\mu\nu,j}$ in [this section](#step3); we have also defined the spatial derivatives of spatial components of $b^\mu$, $b^i_{,k}$ in [this section](#bideriv). Notice the above expression requires spatial derivatives of the *zeroth* component of $b^\mu$ as well, $b^0_{,j}$, which we will now compute. Starting with the definition, and applying the quotient rule:
# \begin{align}
# b^0 &= \frac{u_k B^k}{\sqrt{4\pi}\alpha}, \\
# \rightarrow b^0_{,j} &= \frac{1}{\sqrt{4\pi}} \frac{\alpha \left( u_{k,j} B^k + u_k B^k_{,j} \right) - u_k B^k \alpha_{,j}}{\alpha^2} \\
# &= \frac{\alpha u_{k,j} B^k + \alpha u_k B^k_{,j} - \alpha_{,j} u_k B^k}{\sqrt{4\pi} \alpha^2}.
# \end{align}
# We will first code the numerator, and then divide through by the denominator.
# Step 2.2.c: Construct the derivative of b^2
# First construct the derivative b^0_{,j}
# This four-vector will make b^2 simpler:
smallb4UdD = ixp.zerorank2(DIM=4)
# Fill in the zeroth component
for j in range(DIM):
for k in range(DIM):
# The numerator: \alpha u_{k,j} B^k
# + \alpha u_k B^k_{,j}
# - \alpha_{,j} u_k B^k
smallb4UdD[0][j + 1] += alpha * uD_dD[k][j] * BU[k] + alpha * uD[
k] * BUdD[k][j] - alpha_dD[j] * uD[k] * BU[k]
for j in range(DIM):
# Divide through by the denominator: \sqrt{4\pi} \alpha^2
smallb4UdD[0][j + 1] /= sp.sqrt(4 * M_PI) * alpha * alpha
# At this point, both $b^0_{\ ,j}$ and $b^i_{\ ,j}$ have been computed, but one exists inconveniently in the $4\times 4$ component $\verb|smallb4UdD[][]|$ and the other in the $3\times 3$ component $\verb|smallbUdD[][]|$. So that we can perform full implied sums over $g_{\mu\nu} b^\mu_{,j} b^\nu$ more conveniently, we will now store all information from $\verb|smallbUdD[i][j]|$ into $\verb|smallb4UdD[i+1][j+1]|$:
# Now, we'll fill out the rest of the four-vector with b^i_{,j} that we derived above.
for i in range(DIM):
for j in range(DIM):
smallb4UdD[i + 1][j + 1] = smallbUdD[i][j]
# Using 4-component (Greek-indexed) quantities, we can now complete our construction of
# $$\left(b^2\right)_{,j} = g_{\mu\nu,j} b^\mu b^\nu + 2 g_{\mu\nu} b^\mu_{,j} b^\nu:$$
smallb2_dD = ixp.zerorank1()
for j in range(DIM):
for mu in range(4):
for nu in range(4):
# g_{\mu\nu,j} b^\mu b^\nu
# + 2 g_{\mu\nu} b^\mu_{,j} b^\nu
smallb2_dD[j] += g4DDdD[mu][nu][j + 1] * smallb4U[
mu] * smallb4U[nu] + 2 * g4DD[mu][nu] * smallb4UdD[mu][
j + 1] * smallb4U[nu]
# <a id='gupijderiv'></a>
#
# ## Step 2.2.d: Derivatives of $g^{\mu\nu}$
# $$\label{gupijderiv}$$
#
# \[Back to [List of Derivatives](#table2)\]
#
# We will need derivatives of the inverse four-metric, as well. Let us begin with $g^{00}$: since $g^{00} = -1/\alpha^2$ ([Gourgoulhon, eq. 4.49](https://arxiv.org/pdf/gr-qc/0703035.pdf)), $$g^{00}_{\ ,k} = \frac{2 \alpha_{,k}}{\alpha^3}$$
#
# Step 2.2.d: Construct derivatives of the components of g^{\mu\nu}
g4UUdD = ixp.zerorank3(DIM=4)
for k in range(DIM):
# 2 \alpha_{,k} / \alpha^3
g4UUdD[0][0][k + 1] = 2 * alpha_dD[k] / alpha**3
# Now, we will code the $g^{i0}_{\ ,k}$ and $g^{0j}_{\ ,k}$ components. According to [Gourgoulhon, eq. 4.49](https://arxiv.org/pdf/gr-qc/0703035.pdf), $g^{i0} = g^{0i} = \beta^i/\alpha^2$, so $$g^{i0}_{\ ,k} = g^{0i}_{\ ,k} = \frac{\alpha^2 \beta^i_{,k} - 2 \beta^i \alpha \alpha_{,k}}{\alpha^4}$$ by the quotient rule. So, we'll code
# $$
# g^{i0} = g^{0i} =
# \underbrace{\frac{\beta^i_{,k}}{\alpha^2}}_{\rm Term\ 1}
# - \underbrace{\frac{2 \beta^i \alpha_{,k}}{\alpha^3}}_{\rm Term\ 2}
# $$
for k in range(DIM):
for i in range(DIM):
# Term 1: \beta^i_{,k} / \alpha^2
g4UUdD[i + 1][0][k +
1] = g4UUdD[0][i +
1][k +
1] = betaU_dD[i][k] / alpha**2
for k in range(DIM):
for i in range(DIM):
# Term 2: -2 \beta^i \alpha_{,k} / \alpha^3
g4UUdD[i + 1][0][k + 1] += -2 * betaU[i] * alpha_dD[k] / alpha**3
g4UUdD[0][i + 1][k + 1] += -2 * betaU[i] * alpha_dD[k] / alpha**3
# We will also need derivatives of the spatial part of the inverse four-metric: since $g^{ij} = \gamma^{ij} - \frac{\beta^i \beta^j}{\alpha^2}$ ([Gourgoulhon, eq. 4.49](https://arxiv.org/pdf/gr-qc/0703035.pdf)),
# \begin{align}
# g^{ij}_{\ ,k} &= \gamma^{ij}_{\ ,k} - \frac{\alpha^2 \partial_k (\beta^i \beta^j) - \beta^i \beta^j \partial_k \alpha^2}{(\alpha^2)^2} \\
# &= \gamma^{ij}_{\ ,k} - \frac{\alpha^2\beta^i \beta^j_{,k}+\alpha^2\beta^i_{,k} \beta^j-2\beta^i \beta^j \alpha \alpha_{,k}}{\alpha^4}. \\
# &= \gamma^{ij}_{\ ,k} - \frac{\alpha\beta^i \beta^j_{,k}+\alpha\beta^i_{,k} \beta^j-2\beta^i \beta^j \alpha_{,k}}{\alpha^3} \\
# g^{ij}_{\ ,k} &= \underbrace{\gamma^{ij}_{\ ,k}}_{\rm Term\ 1} - \underbrace{\frac{\beta^i \beta^j_{,k}}{\alpha^2}}_{\rm Term\ 2} - \underbrace{\frac{\beta^i_{,k} \beta^j}{\alpha^2}}_{\rm Term\ 3} + \underbrace{\frac{2\beta^i \beta^j \alpha_{,k}}{\alpha^3}}_{\rm Term\ 4}. \\
# \end{align}
#
gammaUU_dD = ixp.declarerank3("gammaUU_dD", "sym01")
# The spatial derivatives of the spatial components of the four metric:
# Term 1: \gamma^{ij}_{\ ,k}
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
g4UUdD[i + 1][j + 1][k + 1] = gammaUU_dD[i][j][k]
# Term 2: - \beta^i \beta^j_{,k} / \alpha^2
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
g4UUdD[i + 1][j +
1][k +
1] += -betaU[i] * betaU_dD[j][k] / alpha**2
# Term 3: - \beta^i_{,k} \beta^j / \alpha^2
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
g4UUdD[i + 1][j +
1][k +
1] += -betaU_dD[i][k] * betaU[j] / alpha**2
# Term 4: 2\beta^i \beta^j \alpha_{,k}\alpha^3
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
g4UUdD[i + 1][j + 1][
k + 1] += 2 * betaU[i] * betaU[j] * alpha_dD[k] / alpha**3
# <a id='alltogether'></a>
#
# ## Step 2.2.e: Putting it together:
# $$\label{alltogether}$$
#
# \[Back to [List of Derivatives](#table2)\]
#
# So, we can now put it all together, starting from the expression we derived above in [Step 2.2](#step6):
# \begin{align}
# \partial_j T^{j}_{{\rm EM} i} =& \
# \underbrace{g_{\mu i,j} T^{\mu j}_{\rm EM}}_{\rm Term\ 1} \\
# & + \underbrace{g_{\mu i} \left( b^2 u^j_{,j} u^\mu + b^2 u^j u^\mu_{,j} + \frac{b^2}{2} g^{j\mu}_{\ ,j} + b^j_{,j} b^\mu + b^j b^\mu_{,j} \right)}_{\rm Term\ 2} \\
# & + \underbrace{g_{\mu i} \left( \left(b^2\right)_{,j} u^j u^\mu + \frac{1}{2} \left(b^2\right)_{,j} g^{j\mu} \right).}_{\rm Term\ 3} \\
# \end{align}
#
# <a id='alltogether1'></a>
#
# ### Step 2.2.e.i: Putting it together: Term 1
# $$\label{alltogether1}$$
#
# \[Back to [List of Derivatives](#table2)\]
#
# We will now construct this term by term. Term 1 is straightforward: $${\rm Term\ 1} = \gamma_{\mu i,j} T^{\mu j}_{\rm EM}.$$
# Step 2.2.e: Construct TEMUDdD_contracted itself
# Step 2.2.e.i
TEMUDdD_contracted = ixp.zerorank1()
for i in range(DIM):
for j in range(DIM):
for mu in range(4):
# Term 1: g_{\mu i,j} T^{\mu j}_{\rm EM}
TEMUDdD_contracted[i] += g4DDdD[mu][i + 1][j +
1] * T4EMUU[mu][j +
1]
# We'll need derivatives of u4U for the next part:
u4UdD = ixp.zerorank2(DIM=4)
u4upperZero_dD = ixp.declarerank1(
"u4upperZero_dD"
) # Note that derivatives can't be done in 4-D with the current version of NRPy
for i in range(DIM):
u4UdD[0][i + 1] = u4upperZero_dD[i]
for i in range(DIM):
for j in range(DIM):
u4UdD[i + 1][j + 1] = uU_dD[i][j]
# <a id='alltogether2'></a>
#
# ### Step 2.2.e.ii: Putting it together: Term 2
# $$\label{alltogether2}$$
#
# \[Back to [List of Derivatives](#table2)\]
#
# We will now add $${\rm Term\ 2} = g_{\mu i} \left( \underbrace{b^2 u^j_{,j} u^\mu}_{\rm Term\ 2a} + \underbrace{b^2 u^j u^\mu_{,j}}_{\rm Term\ 2b} + \underbrace{\frac{b^2}{2} g^{j\mu}_{\ ,j}}_{\rm Term\ 2c} + \underbrace{b^j_{,j} b^\mu}_{\rm Term\ 2d} + \underbrace{b^j b^\mu_{,j}}_{\rm Term\ 2e} \right)$$ to $\partial_j T^{j}_{{\rm EM} i}$. These are the terms that involve contractions over $k$ (but no metric derivatives like Term 1 had).
#
# Step 2.2.e.ii
for i in range(DIM):
for j in range(DIM):
for mu in range(4):
# Term 2a: g_{\mu i} b^2 u^j_{,j} u^\mu
TEMUDdD_contracted[i] += g4DD[mu][
i + 1] * smallb2 * uU_dD[j][j] * u4U[mu]
for i in range(DIM):
for j in range(DIM):
for mu in range(4):
# Term 2b: g_{\mu i} b^2 u^j u^\mu_{,j}
TEMUDdD_contracted[i] += g4DD[mu][
i + 1] * smallb2 * uU[j] * u4UdD[mu][j + 1]
for i in range(DIM):
for j in range(DIM):
for mu in range(4):
# Term 2c: g_{\mu i} b^2 g^{j \mu}_{,j} / 2
TEMUDdD_contracted[i] += g4DD[mu][i + 1] * smallb2 * g4UUdD[
j + 1][mu][j + 1] / 2
for i in range(DIM):
for j in range(DIM):
for mu in range(4):
# Term 2d: g_{\mu i} b^j_{,j} b^\mu
TEMUDdD_contracted[i] += g4DD[mu][
i + 1] * smallbUdD[j][j] * smallb4U[mu]
for i in range(DIM):
for j in range(DIM):
for mu in range(4):
# Term 2e: g_{\mu i} b^j b^\mu_{,j}
TEMUDdD_contracted[i] += g4DD[mu][i + 1] * smallb4U[
j + 1] * smallb4UdD[mu][j + 1]
# <a id='alltogether3'></a>
#
# ### Step 2.2.e.iii: Putting it together: Term 3
# $$\label{alltogether3}$$
#
# \[Back to [List of Derivatives](#table2)\]
#
# Now, we will add $${\rm Term\ 3} = g_{\mu i} \left( \underbrace{\left(b^2\right)_{,j} u^j u^\mu}_{\rm Term\ 3a} + \underbrace{\frac{1}{2} \left(b^2\right)_{,j} g^{j\mu}}_{\rm Term\ 3b} \right).$$
# Step 2.2.e.iii
for i in range(DIM):
for j in range(DIM):
for mu in range(4):
# Term 3a: g_{\mu i} ( b^2 )_{,j} u^j u^\mu
TEMUDdD_contracted[i] += g4DD[mu][
i + 1] * smallb2_dD[j] * uU[j] * u4U[mu]
for i in range(DIM):
for j in range(DIM):
for mu in range(4):
# Term 3b: g_{mu i} ( b^2 )_{,j} g^{j\mu} / 2
TEMUDdD_contracted[i] += g4DD[mu][
i + 1] * smallb2_dD[j] * g4UU[j + 1][mu] / 2
#
# # Evolution equation for $\tilde{S}_i$
# <a id='step7'></a>
#
# ## Step 3.0: Construct the evolution equation for $\tilde{S}_i$
# $$\label{step7}$$
#
# \[Back to [top](#top)\]
#
# Finally, we will return our attention to the time evolution equation (from eq. 13 of the [original paper](https://arxiv.org/pdf/1704.00599.pdf)),
# \begin{align}
# \partial_t \tilde{S}_i &= - \partial_j \left( \alpha \sqrt{\gamma} T^j_{{\rm EM} i} \right) + \frac{1}{2} \alpha \sqrt{\gamma} T^{\mu \nu}_{\rm EM} \partial_i g_{\mu \nu} \\
# &= -T^j_{{\rm EM} i} \partial_j (\alpha \sqrt{\gamma}) - \alpha \sqrt{\gamma} \partial_j T^j_{{\rm EM} i} + \frac{1}{2} \alpha \sqrt{\gamma} T^{\mu \nu}_{\rm EM} \partial_i g_{\mu \nu} \\
# &= \underbrace{-g_{i\mu} T^{\mu j}_{\rm EM} \partial_j (\alpha \sqrt{\gamma})
# }_{\rm Term\ 1} - \underbrace{\alpha \sqrt{\gamma} \partial_j T^j_{{\rm EM} i}}_{\rm Term\ 2} + \underbrace{\frac{1}{2} \alpha \sqrt{\gamma} T^{\mu \nu}_{\rm EM} \partial_i g_{\mu \nu}}_{\rm Term\ 3} .
# \end{align}
# We will first take derivatives of $\alpha \sqrt{\gamma}$, then construct each term in turn.
# Step 3.0: Construct the evolution equation for \tilde{S}_i
# Here, we set up the necessary machinery to take FD derivatives of alpha * sqrt(gamma)
global alpsqrtgam
alpsqrtgam = gri.register_gridfunctions("AUX", "alpsqrtgam")
alpsqrtgam = alpha * sp.sqrt(gammadet)
alpsqrtgam_dD = ixp.declarerank1("alpsqrtgam_dD")
global Stilde_rhsD
Stilde_rhsD = ixp.zerorank1()
# The first term: g_{i\mu} T^{\mu j}_{\rm EM} \partial_j (\alpha \sqrt{\gamma})
for i in range(DIM):
for j in range(DIM):
for mu in range(4):
Stilde_rhsD[i] += -g4DD[i + 1][mu] * T4EMUU[mu][
j + 1] * alpsqrtgam_dD[j]
# The second term: \alpha \sqrt{\gamma} \partial_j T^j_{{\rm EM} i}
for i in range(DIM):
Stilde_rhsD[i] += -alpsqrtgam * TEMUDdD_contracted[i]
# The third term: \alpha \sqrt{\gamma} T^{\mu \nu}_{\rm EM} \partial_i g_{\mu \nu} / 2
for i in range(DIM):
for mu in range(4):
for nu in range(4):
Stilde_rhsD[i] += alpsqrtgam * T4EMUU[mu][nu] * g4DDdD[mu][nu][
i + 1] / 2
# # Evolution equations for $A_i$ and $\Phi$
# <a id='step8'></a>
#
# ## Step 4.0: Construct the evolution equations for $A_i$ and $[\sqrt{\gamma}\Phi]$
# $$\label{step8}$$
#
# \[Back to [top](#top)\]
#
# We will also need to evolve the vector potential $A_i$. This evolution is given as eq. 17 in the [$\texttt{GiRaFFE}$](https://arxiv.org/pdf/1704.00599.pdf) paper:
# $$\boxed{\partial_t A_i = \epsilon_{ijk} v^j B^k - \partial_i (\underbrace{\alpha \Phi - \beta^j A_j}_{\rm AevolParen}),}$$
# where $\epsilon_{ijk} = [ijk] \sqrt{\gamma}$ is the antisymmetric Levi-Civita tensor, the drift velocity $v^i = u^i/u^0$, $\gamma$ is the determinant of the three metric, $B^k$ is the magnetic field, $\alpha$ is the lapse, and $\beta$ is the shift.
# The scalar electric potential $\Phi$ is also evolved by eq. 19:
# $$\boxed{\partial_t [\sqrt{\gamma} \Phi] = -\partial_j (\underbrace{\alpha\sqrt{\gamma}A^j - \beta^j [\sqrt{\gamma} \Phi]}_{\rm PevolParenU[j]}) - \xi \alpha [\sqrt{\gamma} \Phi],}$$
# with $\xi$ chosen as a damping factor.
#
# ### Step 4.0.a: Construct some useful auxiliary gridfunctions for the other evolution equations
#
# After declaring a some needed quantities, we will also define the parenthetical terms (underbrace above) that we need to take derivatives of. That way, we can take finite-difference derivatives easily. Note that we use $A^j = \gamma^{ij} A_i$, while $A_i$ (with $\Phi$) is technically a four-vector; this is justified, however, since $n_\mu A^\mu = 0$, where $n_\mu$ is a normal to the hypersurface, $A^0=0$ (according to Sec. II, subsection C of [this paper](https://arxiv.org/pdf/1110.4633.pdf)).
# Step 4.0: Construct the evolution equations for A_i and sqrt(gamma)Phi
# Step 4.0.a: Construct some useful auxiliary gridfunctions for the other evolution equations
xi = par.Cparameters(
"REAL", thismodule, "xi", 0.1
) # The (dimensionful) Lorenz damping factor. Recommendation: set to ~1.5/max(delta t).
# Define sqrt(gamma)Phi as psi6Phi
psi6Phi = gri.register_gridfunctions("EVOL", "psi6Phi")
Phi = psi6Phi / sp.sqrt(gammadet)
# We'll define a few extra gridfunctions to avoid complicated derivatives
global AevolParen, PevolParenU
AevolParen = gri.register_gridfunctions("AUX", "AevolParen")
PevolParenU = ixp.register_gridfunctions_for_single_rank1(
"AUX", "PevolParenU")
# {\rm AevolParen} = \alpha \Phi - \beta^j A_j
AevolParen = alpha * Phi
for j in range(DIM):
AevolParen += -betaU[j] * AD[j]
# {\rm PevolParenU[j]} = \alpha\sqrt{\gamma} \gamma^{ij} A_i - \beta^j [\sqrt{\gamma} \Phi]
for j in range(DIM):
PevolParenU[j] = -betaU[j] * psi6Phi
for i in range(DIM):
PevolParenU[j] += alpha * sp.sqrt(gammadet) * gammaUU[i][j] * AD[i]
AevolParen_dD = ixp.declarerank1("AevolParen_dD")
PevolParenU_dD = ixp.declarerank2("PevolParenU_dD", "nosym")
# ### Step 4.0.b: Construct the actual evolution equations for $A_i$ and $[\sqrt{\gamma}\Phi]$
#
# Now to set the evolution equations ([eqs. 17 and 19](https://arxiv.org/pdf/1704.00599.pdf)), recalling that the drift velocity $v^i = u^i/u^0$:
# \begin{align}
# \partial_t A_i &= \epsilon_{ijk} v^j B^k - \partial_i (\alpha \Phi - \beta^j A_j) \\
# &= \epsilon_{ijk} \frac{u^j}{u^0} B^k - {\rm AevolParen\_dD[i]} \\
# \partial_t [\sqrt{\gamma} \Phi] &= -\partial_j \left(\left(\alpha\sqrt{\gamma}\right)A^j - \beta^j [\sqrt{\gamma} \Phi]\right) - \xi \alpha [\sqrt{\gamma} \Phi] \\
# &= -{\rm PevolParenU\_dD[j][j]} - \xi \alpha [\sqrt{\gamma} \Phi]. \\
# \end{align}
# Step 4.0.b: Construct the actual evolution equations for A_i and sqrt(gamma)Phi
global A_rhsD, psi6Phi_rhs
A_rhsD = ixp.zerorank1()
psi6Phi_rhs = sp.sympify(0)
for i in range(DIM):
A_rhsD[i] = -AevolParen_dD[i]
for j in range(DIM):
for k in range(DIM):
A_rhsD[i] += LeviCivitaTensorDDD[i][j][k] * (
uU[j] / u4upperZero) * BU[k]
psi6Phi_rhs = -xi * alpha * psi6Phi
for j in range(DIM):
psi6Phi_rhs += -PevolParenU_dD[j][j]
def MaxwellCartesian_Evol():
#Step 0: Set the spatial dimension parameter to 3.
par.set_parval_from_str("grid::DIM", 3)
DIM = par.parval_from_str("grid::DIM")
# Step 1: Set the finite differencing order to 4.
# (not needed here)
# par.set_parval_from_str("finite_difference::FD_CENTDERIVS_ORDER", 4)
# Step 2: Register gridfunctions that are needed as input.
_psi = gri.register_gridfunctions(
"EVOL", ["psi"]) # lgtm [py/unused-local-variable]
# Step 3a: Declare the rank-1 indexed expressions E_{i}, A_{i},
# and \partial_{i} \psi. Derivative variables like these
# must have an underscore in them, so the finite
# difference module can parse the variable name properly.
ED = ixp.register_gridfunctions_for_single_rank1("EVOL", "ED")
AD = ixp.register_gridfunctions_for_single_rank1("EVOL", "AD")
psi_dD = ixp.declarerank1("psi_dD")
## Step 3b: Declare the conformal metric tensor and its first
# derivative. These are needed to find the Christoffel
# symbols, which we need for covariant derivatives.
gammaDD = ixp.register_gridfunctions_for_single_rank2(
"AUX", "gammaDD", "sym01") # The AUX or EVOL designation is *not*
# used in diagnostic modules.
gammaDD_dD = ixp.declarerank3("gammaDD_dD", "sym01")
gammaDD_dDD = ixp.declarerank4("gammaDD_dDD", "sym01_sym23")
gammaUU, detgamma = ixp.symm_matrix_inverter3x3(gammaDD)
gammaUU_dD = ixp.declarerank3("gammaDD_dD", "sym01")
# Define the Christoffel symbols
GammaUDD = ixp.zerorank3(DIM)
for i in range(DIM):
for k in range(DIM):
for l in range(DIM):
for m in range(DIM):
GammaUDD[i][k][l] += (sp.Rational(1,2))*gammaUU[i][m]*\
(gammaDD_dD[m][k][l] + gammaDD_dD[m][l][k] - gammaDD_dD[k][l][m])
# Step 3b: Declare the rank-2 indexed expression \partial_{j} A_{i},
# which is not symmetric in its indices.
# Derivative variables like these must have an underscore
# in them, so the finite difference module can parse the
# variable name properly.
AD_dD = ixp.declarerank2("AD_dD", "nosym")
# Step 3c: Declare the rank-3 indexed expression \partial_{jk} A_{i},
# which is symmetric in the two {jk} indices.
AD_dDD = ixp.declarerank3("AD_dDD", "sym12")
# Step 4: Calculate first and second covariant derivatives, and the
# necessary contractions.
# First covariant derivative
# D_{j} A_{i} = A_{i,j} - \Gamma^{k}_{ij} A_{k}
AD_dcovD = ixp.zerorank2()
for i in range(DIM):
for j in range(DIM):
AD_dcovD[i][j] = AD_dD[i][j]
for k in range(DIM):
AD_dcovD[i][j] -= GammaUDD[k][i][j] * AD[k]
# First, we must construct the lowered Christoffel symbols:
# \Gamma_{ijk} = \gamma_{il} \Gamma^l_{jk}
# And raise the index on A:
# A^j = \gamma^{ij} A_i
GammaDDD = ixp.zerorank3()
AU = ixp.zerorank1()
for i in range(DIM):
for j in range(DIM):
AU[j] += gammaUU[i][j] * AD[i]
for k in range(DIM):
for l in range(DIM):
GammaDDD[i][j][k] += gammaDD[i][l] * GammaUDD[l][j][k]
# Covariant second derivative (the bracketed terms):
# D_j D^j A_i = \gamma^{jk} [A_{i,jk} - A^l (\gamma_{li,kj} + \gamma_{kl,ij} - \gamma_{ik,lj})
# + \Gamma_{lik} (\gamma^{lm} A_{m,j} + A_m \gamma^{lm}{}_{,j})
# - (\Gamma^l_{ij} A_{l,k} + \Gamma^l_{jk} A_{i,l})
# + (\Gamma^m_{ij} \Gamma^l_{mk} A_l + \Gamma ^m_{jk} \Gamma^l_{im} A_l)
AD_dcovDD = ixp.zerorank3()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
AD_dcovDD[i][j][k] = AD_dDD[i][j][k]
for l in range(DIM):
# Terms 1 and 3
AD_dcovDD[i][j][k] -= AU[l] * (gammaDD_dDD[l][i][k][j] + gammaDD_dDD[k][l][i][j] - \
gammaDD_dDD[i][k][l][j]) \
+ GammaUDD[l][i][j] * AD_dD[l][k] + GammaUDD[l][j][k] * AD_dD[i][l]
for m in range(DIM):
# Terms 2 and 4
AD_dcovDD[i][j][k] += GammaDDD[l][i][k] * (gammaUU[l][m] * AD_dD[m][j] + AD[m] * gammaUU_dD[l][m][j]) \
+ GammaUDD[m][i][j] * GammaUDD[l][m][k] * AD[l] \
+ GammaUDD[m][j][k] * GammaUDD[l][i][m] * AD[l]
# Covariant divergence
# D_{i} A^{i} = \gamma^{ij} D_{j} A_{i}
DivA = 0
# Gradient of covariant divergence
# DivA_dD_{i} = \gamma^{jk} A_{k;\hat{j}\hat{i}}
DivA_dD = ixp.zerorank1()
# Covariant Laplacian
# LapAD_{i} = \gamma^{jk} A_{i;\hat{j}\hat{k}}
LapAD = ixp.zerorank1()
for i in range(DIM):
for j in range(DIM):
DivA += gammaUU[i][j] * AD_dcovD[i][j]
for k in range(DIM):
DivA_dD[i] += gammaUU[j][k] * AD_dcovDD[k][j][i]
LapAD[i] += gammaUU[j][k] * AD_dcovDD[i][j][k]
global ArhsD, ErhsD, psi_rhs
system = par.parval_from_str("System_to_use")
if system == "System_I":
# Step 5: Define right-hand sides for the evolution.
print("Warning: System I is less stable!")
ArhsD = ixp.zerorank1()
ErhsD = ixp.zerorank1()
for i in range(DIM):
ArhsD[i] = -ED[i] - psi_dD[i]
ErhsD[i] = -LapAD[i] + DivA_dD[i]
psi_rhs = -DivA
elif system == "System_II":
# We inherit here all of the definitions from System I, above
# Step 7a: Register the scalar auxiliary variable \Gamma
Gamma = gri.register_gridfunctions("EVOL", ["Gamma"])
# Step 7b: Declare the ordinary gradient \partial_{i} \Gamma
Gamma_dD = ixp.declarerank1("Gamma_dD")
# Step 8a: Construct the second covariant derivative of the scalar \psi
# \psi_{;\hat{i}\hat{j}} = \psi_{,i;\hat{j}}
# = \psi_{,ij} - \Gamma^{k}_{ij} \psi_{,k}
psi_dDD = ixp.declarerank2("psi_dDD", "sym01")
psi_dcovDD = ixp.zerorank2()
for i in range(DIM):
for j in range(DIM):
psi_dcovDD[i][j] = psi_dDD[i][j]
for k in range(DIM):
psi_dcovDD[i][j] += -GammaUDD[k][i][j] * psi_dD[k]
# Step 8b: Construct the covariant Laplacian of \psi
# Lappsi = ghat^{ij} D_{j} D_{i} \psi
Lappsi = 0
for i in range(DIM):
for j in range(DIM):
Lappsi += gammaUU[i][j] * psi_dcovDD[i][j]
# Step 9: Define right-hand sides for the evolution.
global Gamma_rhs
ArhsD = ixp.zerorank1()
ErhsD = ixp.zerorank1()
for i in range(DIM):
ArhsD[i] = -ED[i] - psi_dD[i]
ErhsD[i] = -LapAD[i] + Gamma_dD[i]
psi_rhs = -Gamma
Gamma_rhs = -Lappsi
else:
print(
"Invalid choice of system: System_to_use must be either System_I or System_II"
)
ED_dD = ixp.declarerank2("ED_dD", "nosym")
global Cviolation
Cviolation = gri.register_gridfunctions("AUX", ["Cviolation"])
Cviolation = sp.sympify(0)
for i in range(DIM):
for j in range(DIM):
Cviolation += gammaUU[i][j] * ED_dD[j][i]
for b in range(DIM):
Cviolation -= gammaUU[i][j] * GammaUDD[b][i][j] * ED[b]
def VacuumMaxwellRHSs():
system = par.parval_from_str("Maxwell.InitialData::System_to_use")
global ArhsU, ErhsU, C, psi_rhs
#Step 0: Set the spatial dimension parameter to 3.
DIM = par.parval_from_str("grid::DIM")
rfm.reference_metric()
# Register gridfunctions that are needed as input.
# Declare the rank-1 indexed expressions E_{i}, A_{i},
# that are to be evolved in time.
# Derivative variables like these must have an underscore
# in them, so the finite difference module can parse
# the variable name properly.
# E^i
EU = ixp.register_gridfunctions_for_single_rank1("EVOL", "EU")
# A^i, _AU is unused
_AU = ixp.register_gridfunctions_for_single_rank1("EVOL", "AU")
# \psi is a scalar function that is time evolved
# _psi is unused
_psi = gri.register_gridfunctions("EVOL", ["psi"])
# \partial_i \psi
psi_dD = ixp.declarerank1("psi_dD")
# \partial_k ( A^i ) --> rank two tensor
AU_dD = ixp.declarerank2("AU_dD", "nosym")
# \partial_k partial_m ( A^i ) --> rank three tensor
AU_dDD = ixp.declarerank3("AU_dDD", "sym12")
EU_dD = ixp.declarerank2("EU_dD", "nosym")
C = gri.register_gridfunctions("AUX", "DivE")
# Equation 12 of https://arxiv.org/abs/gr-qc/0201051
C = EU_dD[0][0] + EU_dD[1][1] + EU_dD[2][2]
if system == "System_I":
print('Currently using ' + system + ' RHSs \n')
# Define right-hand sides for the evolution.
# Equations 10 and 11 from https://arxiv.org/abs/gr-qc/0201051
# \partial_t A^i = E^i - \partial_i \psi
ArhsU = ixp.zerorank1()
# \partial_t E^i = -\partial_j^2 A^i + \partial_j \partial_i A^j
ErhsU = ixp.zerorank1()
# Lorenz gauge condition
# \partial_t \psi = -\partial_i A^i
psi_rhs = sp.sympify(0)
for i in range(DIM):
ArhsU[i] = -EU[i] - psi_dD[i]
psi_rhs -= AU_dD[i][i]
for j in range(DIM):
ErhsU[i] += -AU_dDD[i][j][j] + AU_dDD[j][j][i]
elif system == "System_II":
global Gamma_rhs, G
print('Currently using ' + system + ' RHSs \n')
# We inherit here all of the definitions from System I, above
# Register the scalar auxiliary variable \Gamma
Gamma = gri.register_gridfunctions("EVOL", ["Gamma"])
# Declare the ordinary gradient \partial_{i} \Gamma
Gamma_dD = ixp.declarerank1("Gamma_dD")
# partial_i \partial_j \psi
psi_dDD = ixp.declarerank2("psi_dDD", "sym01")
# Lorenz gauge condition
psi_rhs = -Gamma
# Define right-hand sides for the evolution.
# Equations 10 and 14 https://arxiv.org/abs/gr-qc/0201051
ArhsU = ixp.zerorank1()
ErhsU = ixp.zerorank1()
# Equation 13 of https://arxiv.org/abs/gr-qc/0201051
# G = \Gamma - \partial_i A^i
G = gri.register_gridfunctions("AUX", ["G"])
G = Gamma - AU_dD[0][0] - AU_dD[1][1] - AU_dD[2][2]
# Equation 15 https://arxiv.org/abs/gr-qc/0201051
# Gamma_rhs = -DivE
Gamma_rhs = sp.sympify(0)
for i in range(DIM):
ArhsU[i] = -EU[i] - psi_dD[i]
ErhsU[i] = Gamma_dD[i]
Gamma_rhs -= psi_dDD[i][i]
for j in range(DIM):
ErhsU[i] -= AU_dDD[i][j][j]
else:
print(
"Invalid choice of system: System_to_use must be either System_I or System_II"
)
def GiRaFFE_NRPy_Main_Driver_generate_all(out_dir):
cmd.mkdir(out_dir)
gammaDD = ixp.register_gridfunctions_for_single_rank2("AUXEVOL","gammaDD","sym01",DIM=3)
betaU = ixp.register_gridfunctions_for_single_rank1("AUXEVOL","betaU",DIM=3)
alpha = gri.register_gridfunctions("AUXEVOL","alpha")
AD = ixp.register_gridfunctions_for_single_rank1("EVOL","AD")
BU = ixp.register_gridfunctions_for_single_rank1("AUXEVOL","BU")
ValenciavU = ixp.register_gridfunctions_for_single_rank1("AUXEVOL","ValenciavU")
psi6Phi = gri.register_gridfunctions("EVOL","psi6Phi")
StildeD = ixp.register_gridfunctions_for_single_rank1("EVOL","StildeD")
PhievolParenU = ixp.register_gridfunctions_for_single_rank1("AUXEVOL","PhievolParenU",DIM=3)
AevolParen = gri.register_gridfunctions("AUXEVOL","AevolParen")
GRHD.compute_sqrtgammaDET(gammaDD)
GRFFE.compute_AD_source_term_parenthetical_for_FD(GRHD.sqrtgammaDET,betaU,alpha,psi6Phi,AD)
GRFFE.compute_psi6Phi_rhs_parenthetical(gammaDD,GRHD.sqrtgammaDET,betaU,alpha,AD,psi6Phi)
parens_to_print = [\
lhrh(lhs=gri.gfaccess("auxevol_gfs","AevolParen"),rhs=GRFFE.AevolParen),\
lhrh(lhs=gri.gfaccess("auxevol_gfs","PhievolParenU0"),rhs=GRFFE.PhievolParenU[0]),\
lhrh(lhs=gri.gfaccess("auxevol_gfs","PhievolParenU1"),rhs=GRFFE.PhievolParenU[1]),\
lhrh(lhs=gri.gfaccess("auxevol_gfs","PhievolParenU2"),rhs=GRFFE.PhievolParenU[2]),\
]
subdir = "RHSs"
cmd.mkdir(os.path.join(out_dir, subdir))
desc = "Calculate quantities to be finite-differenced for the GRFFE RHSs"
name = "calculate_parentheticals_for_RHSs"
outCfunction(
outfile = os.path.join(out_dir,subdir,name+".h"), desc=desc, name=name,
params ="const paramstruct *restrict params,const REAL *restrict in_gfs,REAL *restrict auxevol_gfs",
body = fin.FD_outputC("returnstring",parens_to_print,params="outCverbose=False").replace("IDX4","IDX4S"),
loopopts ="AllPoints",
rel_path_for_Cparams=os.path.join("../"))
xi_damping = par.Cparameters("REAL",thismodule,"xi_damping",0.1)
GRFFE.compute_psi6Phi_rhs_damping_term(alpha,psi6Phi,xi_damping)
AevolParen_dD = ixp.declarerank1("AevolParen_dD",DIM=3)
PhievolParenU_dD = ixp.declarerank2("PhievolParenU_dD","nosym",DIM=3)
A_rhsD = ixp.zerorank1()
psi6Phi_rhs = GRFFE.psi6Phi_damping
for i in range(3):
A_rhsD[i] += -AevolParen_dD[i]
psi6Phi_rhs += -PhievolParenU_dD[i][i]
# Add Kreiss-Oliger dissipation to the GRFFE RHSs:
psi6Phi_dKOD = ixp.declarerank1("psi6Phi_dKOD")
AD_dKOD = ixp.declarerank2("AD_dKOD","nosym")
for i in range(3):
psi6Phi_rhs += diss_strength*psi6Phi_dKOD[i]*rfm.ReU[i] # ReU[i] = 1/scalefactor_orthog_funcform[i]
for j in range(3):
A_rhsD[j] += diss_strength*AD_dKOD[j][i]*rfm.ReU[i] # ReU[i] = 1/scalefactor_orthog_funcform[i]
RHSs_to_print = [\
lhrh(lhs=gri.gfaccess("rhs_gfs","AD0"),rhs=A_rhsD[0]),\
lhrh(lhs=gri.gfaccess("rhs_gfs","AD1"),rhs=A_rhsD[1]),\
lhrh(lhs=gri.gfaccess("rhs_gfs","AD2"),rhs=A_rhsD[2]),\
lhrh(lhs=gri.gfaccess("rhs_gfs","psi6Phi"),rhs=psi6Phi_rhs),\
]
desc = "Calculate AD gauge term and psi6Phi RHSs"
name = "calculate_AD_gauge_psi6Phi_RHSs"
source_Ccode = outCfunction(
outfile = "returnstring", desc=desc, name=name,
params ="const paramstruct *params,const REAL *in_gfs,const REAL *auxevol_gfs,REAL *rhs_gfs",
body = fin.FD_outputC("returnstring",RHSs_to_print,params="outCverbose=False").replace("IDX4","IDX4S"),
loopopts ="InteriorPoints",
rel_path_for_Cparams=os.path.join("../")).replace("=NGHOSTS","=NGHOSTS_A2B").replace("NGHOSTS+Nxx0","Nxx_plus_2NGHOSTS0-NGHOSTS_A2B").replace("NGHOSTS+Nxx1","Nxx_plus_2NGHOSTS1-NGHOSTS_A2B").replace("NGHOSTS+Nxx2","Nxx_plus_2NGHOSTS2-NGHOSTS_A2B")
# Note the above .replace() functions. These serve to expand the loop range into the ghostzones, since
# the second-order FD needs fewer than some other algorithms we use do.
with open(os.path.join(out_dir,subdir,name+".h"),"w") as file:
file.write(source_Ccode)
# Declare all the Cparameters we will need
metricderivDDD = ixp.declarerank3("metricderivDDD","sym01",DIM=3)
shiftderivUD = ixp.declarerank2("shiftderivUD","nosym",DIM=3)
lapsederivD = ixp.declarerank1("lapsederivD",DIM=3)
general_access = """const REAL gammaDD00 = auxevol_gfs[IDX4S(GAMMADD00GF,i0,i1,i2)];
const REAL gammaDD01 = auxevol_gfs[IDX4S(GAMMADD01GF,i0,i1,i2)];
const REAL gammaDD02 = auxevol_gfs[IDX4S(GAMMADD02GF,i0,i1,i2)];
const REAL gammaDD11 = auxevol_gfs[IDX4S(GAMMADD11GF,i0,i1,i2)];
const REAL gammaDD12 = auxevol_gfs[IDX4S(GAMMADD12GF,i0,i1,i2)];
const REAL gammaDD22 = auxevol_gfs[IDX4S(GAMMADD22GF,i0,i1,i2)];
const REAL betaU0 = auxevol_gfs[IDX4S(BETAU0GF,i0,i1,i2)];
const REAL betaU1 = auxevol_gfs[IDX4S(BETAU1GF,i0,i1,i2)];
const REAL betaU2 = auxevol_gfs[IDX4S(BETAU2GF,i0,i1,i2)];
const REAL alpha = auxevol_gfs[IDX4S(ALPHAGF,i0,i1,i2)];
const REAL ValenciavU0 = auxevol_gfs[IDX4S(VALENCIAVU0GF,i0,i1,i2)];
const REAL ValenciavU1 = auxevol_gfs[IDX4S(VALENCIAVU1GF,i0,i1,i2)];
const REAL ValenciavU2 = auxevol_gfs[IDX4S(VALENCIAVU2GF,i0,i1,i2)];
const REAL BU0 = auxevol_gfs[IDX4S(BU0GF,i0,i1,i2)];
const REAL BU1 = auxevol_gfs[IDX4S(BU1GF,i0,i1,i2)];
const REAL BU2 = auxevol_gfs[IDX4S(BU2GF,i0,i1,i2)];
"""
metric_deriv_access = ixp.zerorank1(DIM=3)
metric_deriv_access[0] = """const REAL metricderivDDD000 = (auxevol_gfs[IDX4S(GAMMA_FACEDD00GF,i0+1,i1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD00GF,i0,i1,i2)])/dxx0;
const REAL metricderivDDD010 = (auxevol_gfs[IDX4S(GAMMA_FACEDD01GF,i0+1,i1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD01GF,i0,i1,i2)])/dxx0;
const REAL metricderivDDD020 = (auxevol_gfs[IDX4S(GAMMA_FACEDD02GF,i0+1,i1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD02GF,i0,i1,i2)])/dxx0;
const REAL metricderivDDD110 = (auxevol_gfs[IDX4S(GAMMA_FACEDD11GF,i0+1,i1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD11GF,i0,i1,i2)])/dxx0;
const REAL metricderivDDD120 = (auxevol_gfs[IDX4S(GAMMA_FACEDD12GF,i0+1,i1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD12GF,i0,i1,i2)])/dxx0;
const REAL metricderivDDD220 = (auxevol_gfs[IDX4S(GAMMA_FACEDD22GF,i0+1,i1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD22GF,i0,i1,i2)])/dxx0;
const REAL shiftderivUD00 = (auxevol_gfs[IDX4S(BETA_FACEU0GF,i0+1,i1,i2)]-auxevol_gfs[IDX4S(BETA_FACEU0GF,i0,i1,i2)])/dxx0;
const REAL shiftderivUD10 = (auxevol_gfs[IDX4S(BETA_FACEU1GF,i0+1,i1,i2)]-auxevol_gfs[IDX4S(BETA_FACEU1GF,i0,i1,i2)])/dxx0;
const REAL shiftderivUD20 = (auxevol_gfs[IDX4S(BETA_FACEU2GF,i0+1,i1,i2)]-auxevol_gfs[IDX4S(BETA_FACEU2GF,i0,i1,i2)])/dxx0;
const REAL lapsederivD0 = (auxevol_gfs[IDX4S(ALPHA_FACEGF,i0+1,i1,i2)]-auxevol_gfs[IDX4S(ALPHA_FACEGF,i0,i1,i2)])/dxx0;
REAL Stilde_rhsD0;
"""
metric_deriv_access[1] = """const REAL metricderivDDD001 = (auxevol_gfs[IDX4S(GAMMA_FACEDD00GF,i0,i1+1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD00GF,i0,i1,i2)])/dxx1;
const REAL metricderivDDD011 = (auxevol_gfs[IDX4S(GAMMA_FACEDD01GF,i0,i1+1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD01GF,i0,i1,i2)])/dxx1;
const REAL metricderivDDD021 = (auxevol_gfs[IDX4S(GAMMA_FACEDD02GF,i0,i1+1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD02GF,i0,i1,i2)])/dxx1;
const REAL metricderivDDD111 = (auxevol_gfs[IDX4S(GAMMA_FACEDD11GF,i0,i1+1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD11GF,i0,i1,i2)])/dxx1;
const REAL metricderivDDD121 = (auxevol_gfs[IDX4S(GAMMA_FACEDD12GF,i0,i1+1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD12GF,i0,i1,i2)])/dxx1;
const REAL metricderivDDD221 = (auxevol_gfs[IDX4S(GAMMA_FACEDD22GF,i0,i1+1,i2)]-auxevol_gfs[IDX4S(GAMMA_FACEDD22GF,i0,i1,i2)])/dxx1;
const REAL shiftderivUD01 = (auxevol_gfs[IDX4S(BETA_FACEU0GF,i0,i1+1,i2)]-auxevol_gfs[IDX4S(BETA_FACEU0GF,i0,i1,i2)])/dxx1;
const REAL shiftderivUD11 = (auxevol_gfs[IDX4S(BETA_FACEU1GF,i0,i1+1,i2)]-auxevol_gfs[IDX4S(BETA_FACEU1GF,i0,i1,i2)])/dxx1;
const REAL shiftderivUD21 = (auxevol_gfs[IDX4S(BETA_FACEU2GF,i0,i1+1,i2)]-auxevol_gfs[IDX4S(BETA_FACEU2GF,i0,i1,i2)])/dxx1;
const REAL lapsederivD1 = (auxevol_gfs[IDX4S(ALPHA_FACEGF,i0,i1+1,i2)]-auxevol_gfs[IDX4S(ALPHA_FACEGF,i0,i1,i2)])/dxx1;
REAL Stilde_rhsD1;
"""
metric_deriv_access[2] = """const REAL metricderivDDD002 = (auxevol_gfs[IDX4S(GAMMA_FACEDD00GF,i0,i1,i2+1)]-auxevol_gfs[IDX4S(GAMMA_FACEDD00GF,i0,i1,i2)])/dxx2;
const REAL metricderivDDD012 = (auxevol_gfs[IDX4S(GAMMA_FACEDD01GF,i0,i1,i2+1)]-auxevol_gfs[IDX4S(GAMMA_FACEDD01GF,i0,i1,i2)])/dxx2;
const REAL metricderivDDD022 = (auxevol_gfs[IDX4S(GAMMA_FACEDD02GF,i0,i1,i2+1)]-auxevol_gfs[IDX4S(GAMMA_FACEDD02GF,i0,i1,i2)])/dxx2;
const REAL metricderivDDD112 = (auxevol_gfs[IDX4S(GAMMA_FACEDD11GF,i0,i1,i2+1)]-auxevol_gfs[IDX4S(GAMMA_FACEDD11GF,i0,i1,i2)])/dxx2;
const REAL metricderivDDD122 = (auxevol_gfs[IDX4S(GAMMA_FACEDD12GF,i0,i1,i2+1)]-auxevol_gfs[IDX4S(GAMMA_FACEDD12GF,i0,i1,i2)])/dxx2;
const REAL metricderivDDD222 = (auxevol_gfs[IDX4S(GAMMA_FACEDD22GF,i0,i1,i2+1)]-auxevol_gfs[IDX4S(GAMMA_FACEDD22GF,i0,i1,i2)])/dxx2;
const REAL shiftderivUD02 = (auxevol_gfs[IDX4S(BETA_FACEU0GF,i0,i1,i2+1)]-auxevol_gfs[IDX4S(BETA_FACEU0GF,i0,i1,i2)])/dxx2;
const REAL shiftderivUD12 = (auxevol_gfs[IDX4S(BETA_FACEU1GF,i0,i1,i2+1)]-auxevol_gfs[IDX4S(BETA_FACEU1GF,i0,i1,i2)])/dxx2;
const REAL shiftderivUD22 = (auxevol_gfs[IDX4S(BETA_FACEU2GF,i0,i1,i2+1)]-auxevol_gfs[IDX4S(BETA_FACEU2GF,i0,i1,i2)])/dxx2;
const REAL lapsederivD2 = (auxevol_gfs[IDX4S(ALPHA_FACEGF,i0,i1,i2+1)]-auxevol_gfs[IDX4S(ALPHA_FACEGF,i0,i1,i2)])/dxx2;
REAL Stilde_rhsD2;
"""
write_final_quantity = ixp.zerorank1(DIM=3)
write_final_quantity[0] = """rhs_gfs[IDX4S(STILDED0GF,i0,i1,i2)] += Stilde_rhsD0;
"""
write_final_quantity[1] = """rhs_gfs[IDX4S(STILDED1GF,i0,i1,i2)] += Stilde_rhsD1;
"""
write_final_quantity[2] = """rhs_gfs[IDX4S(STILDED2GF,i0,i1,i2)] += Stilde_rhsD2;
"""
# Declare this symbol:
sqrt4pi = par.Cparameters("REAL",thismodule,"sqrt4pi","sqrt(4.0*M_PI)")
# We need to rerun a few of these functions with the reset lists to make sure these functions
# don't cheat by using analytic expressions
GRHD.u4U_in_terms_of_ValenciavU__rescale_ValenciavU_by_applying_speed_limit(alpha, betaU, gammaDD, ValenciavU)
GRFFE.compute_smallb4U(gammaDD, betaU, alpha, GRHD.u4U_ito_ValenciavU, BU, sqrt4pi)
GRFFE.compute_smallbsquared(gammaDD, betaU, alpha, GRFFE.smallb4U)
GRFFE.compute_TEM4UU(gammaDD,betaU,alpha, GRFFE.smallb4U, GRFFE.smallbsquared,GRHD.u4U_ito_ValenciavU)
GRHD.compute_g4DD_zerotimederiv_dD(gammaDD,betaU,alpha, metricderivDDD,shiftderivUD,lapsederivD)
GRHD.compute_S_tilde_source_termD(alpha, GRHD.sqrtgammaDET,GRHD.g4DD_zerotimederiv_dD, GRFFE.TEM4UU)
for i in range(3):
desc = "Adds the source term to StildeD"+str(i)+"."
name = "calculate_StildeD"+str(i)+"_source_term"
outCfunction(
outfile = os.path.join(out_dir,subdir,name+".h"), desc=desc, name=name,
params ="const paramstruct *params,const REAL *auxevol_gfs, REAL *rhs_gfs",
body = general_access \
+metric_deriv_access[i]\
+outputC(GRHD.S_tilde_source_termD[i],"Stilde_rhsD"+str(i),"returnstring",params="outCverbose=False").replace("IDX4","IDX4S")\
+write_final_quantity[i],
loopopts ="InteriorPoints",
rel_path_for_Cparams=os.path.join("../"))
subdir = "FCVAL"
cmd.mkdir(os.path.join(out_dir, subdir))
FCVAL.GiRaFFE_NRPy_FCVAL(os.path.join(out_dir,subdir))
subdir = "PPM"
cmd.mkdir(os.path.join(out_dir, subdir))
PPM.GiRaFFE_NRPy_PPM(os.path.join(out_dir,subdir))
# We will pass values of the gridfunction on the cell faces into the function. This requires us
# to declare them as C parameters in NRPy+. We will denote this with the _face infix/suffix.
alpha_face = gri.register_gridfunctions("AUXEVOL","alpha_face")
gamma_faceDD = ixp.register_gridfunctions_for_single_rank2("AUXEVOL","gamma_faceDD","sym01")
beta_faceU = ixp.register_gridfunctions_for_single_rank1("AUXEVOL","beta_faceU")
# We'll need some more gridfunctions, now, to represent the reconstructions of BU and ValenciavU
# on the right and left faces
Valenciav_rU = ixp.register_gridfunctions_for_single_rank1("AUXEVOL","Valenciav_rU",DIM=3)
B_rU = ixp.register_gridfunctions_for_single_rank1("AUXEVOL","B_rU",DIM=3)
Valenciav_lU = ixp.register_gridfunctions_for_single_rank1("AUXEVOL","Valenciav_lU",DIM=3)
B_lU = ixp.register_gridfunctions_for_single_rank1("AUXEVOL","B_lU",DIM=3)
Memory_Read = """const double alpha_face = auxevol_gfs[IDX4S(ALPHA_FACEGF, i0,i1,i2)];
const double gamma_faceDD00 = auxevol_gfs[IDX4S(GAMMA_FACEDD00GF, i0,i1,i2)];
const double gamma_faceDD01 = auxevol_gfs[IDX4S(GAMMA_FACEDD01GF, i0,i1,i2)];
const double gamma_faceDD02 = auxevol_gfs[IDX4S(GAMMA_FACEDD02GF, i0,i1,i2)];
const double gamma_faceDD11 = auxevol_gfs[IDX4S(GAMMA_FACEDD11GF, i0,i1,i2)];
const double gamma_faceDD12 = auxevol_gfs[IDX4S(GAMMA_FACEDD12GF, i0,i1,i2)];
const double gamma_faceDD22 = auxevol_gfs[IDX4S(GAMMA_FACEDD22GF, i0,i1,i2)];
const double beta_faceU0 = auxevol_gfs[IDX4S(BETA_FACEU0GF, i0,i1,i2)];
const double beta_faceU1 = auxevol_gfs[IDX4S(BETA_FACEU1GF, i0,i1,i2)];
const double beta_faceU2 = auxevol_gfs[IDX4S(BETA_FACEU2GF, i0,i1,i2)];
const double Valenciav_rU0 = auxevol_gfs[IDX4S(VALENCIAV_RU0GF, i0,i1,i2)];
const double Valenciav_rU1 = auxevol_gfs[IDX4S(VALENCIAV_RU1GF, i0,i1,i2)];
const double Valenciav_rU2 = auxevol_gfs[IDX4S(VALENCIAV_RU2GF, i0,i1,i2)];
const double B_rU0 = auxevol_gfs[IDX4S(B_RU0GF, i0,i1,i2)];
const double B_rU1 = auxevol_gfs[IDX4S(B_RU1GF, i0,i1,i2)];
const double B_rU2 = auxevol_gfs[IDX4S(B_RU2GF, i0,i1,i2)];
const double Valenciav_lU0 = auxevol_gfs[IDX4S(VALENCIAV_LU0GF, i0,i1,i2)];
const double Valenciav_lU1 = auxevol_gfs[IDX4S(VALENCIAV_LU1GF, i0,i1,i2)];
const double Valenciav_lU2 = auxevol_gfs[IDX4S(VALENCIAV_LU2GF, i0,i1,i2)];
const double B_lU0 = auxevol_gfs[IDX4S(B_LU0GF, i0,i1,i2)];
const double B_lU1 = auxevol_gfs[IDX4S(B_LU1GF, i0,i1,i2)];
const double B_lU2 = auxevol_gfs[IDX4S(B_LU2GF, i0,i1,i2)];
REAL A_rhsD0 = 0; REAL A_rhsD1 = 0; REAL A_rhsD2 = 0;
"""
Memory_Write = """rhs_gfs[IDX4S(AD0GF,i0,i1,i2)] += A_rhsD0;
rhs_gfs[IDX4S(AD1GF,i0,i1,i2)] += A_rhsD1;
rhs_gfs[IDX4S(AD2GF,i0,i1,i2)] += A_rhsD2;
"""
indices = ["i0","i1","i2"]
indicesp1 = ["i0+1","i1+1","i2+1"]
subdir = "RHSs"
for flux_dirn in range(3):
Af.calculate_E_i_flux(flux_dirn,True,alpha_face,gamma_faceDD,beta_faceU,\
Valenciav_rU,B_rU,Valenciav_lU,B_lU)
E_field_to_print = [\
sp.Rational(1,4)*Af.E_fluxD[(flux_dirn+1)%3],
sp.Rational(1,4)*Af.E_fluxD[(flux_dirn+2)%3],
]
E_field_names = [\
"A_rhsD"+str((flux_dirn+1)%3),
"A_rhsD"+str((flux_dirn+2)%3),
]
desc = "Calculate the electric flux on the left face in direction " + str(flux_dirn) + "."
name = "calculate_E_field_D" + str(flux_dirn) + "_right"
outCfunction(
outfile = os.path.join(out_dir,subdir,name+".h"), desc=desc, name=name,
params ="const paramstruct *params,const REAL *auxevol_gfs,REAL *rhs_gfs",
body = Memory_Read \
+outputC(E_field_to_print,E_field_names,"returnstring",params="outCverbose=False").replace("IDX4","IDX4S")\
+Memory_Write,
loopopts ="InteriorPoints",
rel_path_for_Cparams=os.path.join("../"))
desc = "Calculate the electric flux on the left face in direction " + str(flux_dirn) + "."
name = "calculate_E_field_D" + str(flux_dirn) + "_left"
outCfunction(
outfile = os.path.join(out_dir,subdir,name+".h"), desc=desc, name=name,
params ="const paramstruct *params,const REAL *auxevol_gfs,REAL *rhs_gfs",
body = Memory_Read.replace(indices[flux_dirn],indicesp1[flux_dirn]) \
+outputC(E_field_to_print,E_field_names,"returnstring",params="outCverbose=False").replace("IDX4","IDX4S")\
+Memory_Write,
loopopts ="InteriorPoints",
rel_path_for_Cparams=os.path.join("../"))
Memory_Read = """const double alpha_face = auxevol_gfs[IDX4S(ALPHA_FACEGF, i0,i1,i2)];
const double gamma_faceDD00 = auxevol_gfs[IDX4S(GAMMA_FACEDD00GF, i0,i1,i2)];
const double gamma_faceDD01 = auxevol_gfs[IDX4S(GAMMA_FACEDD01GF, i0,i1,i2)];
const double gamma_faceDD02 = auxevol_gfs[IDX4S(GAMMA_FACEDD02GF, i0,i1,i2)];
const double gamma_faceDD11 = auxevol_gfs[IDX4S(GAMMA_FACEDD11GF, i0,i1,i2)];
const double gamma_faceDD12 = auxevol_gfs[IDX4S(GAMMA_FACEDD12GF, i0,i1,i2)];
const double gamma_faceDD22 = auxevol_gfs[IDX4S(GAMMA_FACEDD22GF, i0,i1,i2)];
const double beta_faceU0 = auxevol_gfs[IDX4S(BETA_FACEU0GF, i0,i1,i2)];
const double beta_faceU1 = auxevol_gfs[IDX4S(BETA_FACEU1GF, i0,i1,i2)];
const double beta_faceU2 = auxevol_gfs[IDX4S(BETA_FACEU2GF, i0,i1,i2)];
const double Valenciav_rU0 = auxevol_gfs[IDX4S(VALENCIAV_RU0GF, i0,i1,i2)];
const double Valenciav_rU1 = auxevol_gfs[IDX4S(VALENCIAV_RU1GF, i0,i1,i2)];
const double Valenciav_rU2 = auxevol_gfs[IDX4S(VALENCIAV_RU2GF, i0,i1,i2)];
const double B_rU0 = auxevol_gfs[IDX4S(B_RU0GF, i0,i1,i2)];
const double B_rU1 = auxevol_gfs[IDX4S(B_RU1GF, i0,i1,i2)];
const double B_rU2 = auxevol_gfs[IDX4S(B_RU2GF, i0,i1,i2)];
const double Valenciav_lU0 = auxevol_gfs[IDX4S(VALENCIAV_LU0GF, i0,i1,i2)];
const double Valenciav_lU1 = auxevol_gfs[IDX4S(VALENCIAV_LU1GF, i0,i1,i2)];
const double Valenciav_lU2 = auxevol_gfs[IDX4S(VALENCIAV_LU2GF, i0,i1,i2)];
const double B_lU0 = auxevol_gfs[IDX4S(B_LU0GF, i0,i1,i2)];
const double B_lU1 = auxevol_gfs[IDX4S(B_LU1GF, i0,i1,i2)];
const double B_lU2 = auxevol_gfs[IDX4S(B_LU2GF, i0,i1,i2)];
REAL Stilde_fluxD0 = 0; REAL Stilde_fluxD1 = 0; REAL Stilde_fluxD2 = 0;
"""
Memory_Write = """rhs_gfs[IDX4S(STILDED0GF, i0, i1, i2)] += invdx0*Stilde_fluxD0;
rhs_gfs[IDX4S(STILDED1GF, i0, i1, i2)] += invdx0*Stilde_fluxD1;
rhs_gfs[IDX4S(STILDED2GF, i0, i1, i2)] += invdx0*Stilde_fluxD2;
"""
indices = ["i0","i1","i2"]
indicesp1 = ["i0+1","i1+1","i2+1"]
assignment = "+="
assignmentp1 = "-="
invdx = ["invdx0","invdx1","invdx2"]
for flux_dirn in range(3):
Sf.calculate_Stilde_flux(flux_dirn,True,alpha_face,gamma_faceDD,beta_faceU,\
Valenciav_rU,B_rU,Valenciav_lU,B_lU,sqrt4pi)
Stilde_flux_to_print = [\
Sf.Stilde_fluxD[0],\
Sf.Stilde_fluxD[1],\
Sf.Stilde_fluxD[2],\
]
Stilde_flux_names = [\
"Stilde_fluxD0",\
"Stilde_fluxD1",\
"Stilde_fluxD2",\
]
desc = "Compute the flux of all 3 components of tilde{S}_i on the right face in the " + str(flux_dirn) + "."
name = "calculate_Stilde_flux_D" + str(flux_dirn) + "_right"
outCfunction(
outfile = os.path.join(out_dir,subdir,name+".h"), desc=desc, name=name,
params ="const paramstruct *params,const REAL *auxevol_gfs,REAL *rhs_gfs",
body = Memory_Read \
+outputC(Stilde_flux_to_print,Stilde_flux_names,"returnstring",params="outCverbose=False").replace("IDX4","IDX4S")\
+Memory_Write.replace(invdx[0],invdx[flux_dirn]),
loopopts ="InteriorPoints",
rel_path_for_Cparams=os.path.join("../"))
desc = "Compute the flux of all 3 components of tilde{S}_i on the left face in the " + str(flux_dirn) + "."
name = "calculate_Stilde_flux_D" + str(flux_dirn) + "_left"
outCfunction(
outfile = os.path.join(out_dir,subdir,name+".h"), desc=desc, name=name,
params ="const paramstruct *params,const REAL *auxevol_gfs,REAL *rhs_gfs",
body = Memory_Read.replace(indices[flux_dirn],indicesp1[flux_dirn]) \
+outputC(Stilde_flux_to_print,Stilde_flux_names,"returnstring",params="outCverbose=False").replace("IDX4","IDX4S")\
+Memory_Write.replace(invdx[0],invdx[flux_dirn]).replace(assignment,assignmentp1),
loopopts ="InteriorPoints",
rel_path_for_Cparams=os.path.join("../"))
subdir = "boundary_conditions"
cmd.mkdir(os.path.join(out_dir,subdir))
BC.GiRaFFE_NRPy_BCs(os.path.join(out_dir,subdir))
subdir = "A2B"
cmd.mkdir(os.path.join(out_dir,subdir))
A2B.GiRaFFE_NRPy_A2B(os.path.join(out_dir,subdir),gammaDD,AD,BU)
C2P_P2C.GiRaFFE_NRPy_C2P(StildeD,BU,gammaDD,betaU,alpha)
values_to_print = [\
lhrh(lhs=gri.gfaccess("in_gfs","StildeD0"),rhs=C2P_P2C.outStildeD[0]),\
lhrh(lhs=gri.gfaccess("in_gfs","StildeD1"),rhs=C2P_P2C.outStildeD[1]),\
lhrh(lhs=gri.gfaccess("in_gfs","StildeD2"),rhs=C2P_P2C.outStildeD[2]),\
lhrh(lhs=gri.gfaccess("auxevol_gfs","ValenciavU0"),rhs=C2P_P2C.ValenciavU[0]),\
lhrh(lhs=gri.gfaccess("auxevol_gfs","ValenciavU1"),rhs=C2P_P2C.ValenciavU[1]),\
lhrh(lhs=gri.gfaccess("auxevol_gfs","ValenciavU2"),rhs=C2P_P2C.ValenciavU[2])\
]
subdir = "C2P"
cmd.mkdir(os.path.join(out_dir,subdir))
desc = "Apply fixes to \tilde{S}_i and recompute the velocity to match with current sheet prescription."
name = "GiRaFFE_NRPy_cons_to_prims"
outCfunction(
outfile = os.path.join(out_dir,subdir,name+".h"), desc=desc, name=name,
params ="const paramstruct *params,REAL *xx[3],REAL *auxevol_gfs,REAL *in_gfs",
body = fin.FD_outputC("returnstring",values_to_print,params="outCverbose=False").replace("IDX4","IDX4S"),
loopopts ="AllPoints,Read_xxs",
rel_path_for_Cparams=os.path.join("../"))
C2P_P2C.GiRaFFE_NRPy_P2C(gammaDD,betaU,alpha, ValenciavU,BU, sqrt4pi)
values_to_print = [\
lhrh(lhs=gri.gfaccess("in_gfs","StildeD0"),rhs=C2P_P2C.StildeD[0]),\
lhrh(lhs=gri.gfaccess("in_gfs","StildeD1"),rhs=C2P_P2C.StildeD[1]),\
lhrh(lhs=gri.gfaccess("in_gfs","StildeD2"),rhs=C2P_P2C.StildeD[2]),\
]
desc = "Recompute StildeD after current sheet fix to Valencia 3-velocity to ensure consistency between conservative & primitive variables."
name = "GiRaFFE_NRPy_prims_to_cons"
outCfunction(
outfile = os.path.join(out_dir,subdir,name+".h"), desc=desc, name=name,
params ="const paramstruct *params,REAL *auxevol_gfs,REAL *in_gfs",
body = fin.FD_outputC("returnstring",values_to_print,params="outCverbose=False").replace("IDX4","IDX4S"),
loopopts ="AllPoints",
rel_path_for_Cparams=os.path.join("../"))
# Write out the main driver itself:
with open(os.path.join(out_dir,"GiRaFFE_NRPy_Main_Driver.h"),"w") as file:
file.write("""// Structure to track ghostzones for PPM:
typedef struct __gf_and_gz_struct__ {
REAL *gf;
int gz_lo[4],gz_hi[4];
} gf_and_gz_struct;
// Some additional constants needed for PPM:
const int VX=0,VY=1,VZ=2,BX=3,BY=4,BZ=5;
const int NUM_RECONSTRUCT_GFS = 6;
// Include ALL functions needed for evolution
#include "RHSs/calculate_parentheticals_for_RHSs.h"
#include "RHSs/calculate_AD_gauge_psi6Phi_RHSs.h"
#include "PPM/reconstruct_set_of_prims_PPM_GRFFE_NRPy.c"
#include "FCVAL/interpolate_metric_gfs_to_cell_faces.h"
#include "RHSs/calculate_StildeD0_source_term.h"
#include "RHSs/calculate_StildeD1_source_term.h"
#include "RHSs/calculate_StildeD2_source_term.h"
// #include "RHSs/calculate_E_field_D0_right.h"
// #include "RHSs/calculate_E_field_D0_left.h"
// #include "RHSs/calculate_E_field_D1_right.h"
// #include "RHSs/calculate_E_field_D1_left.h"
// #include "RHSs/calculate_E_field_D2_right.h"
// #include "RHSs/calculate_E_field_D2_left.h"
#include "../calculate_E_field_flat_all_in_one.h"
#include "RHSs/calculate_Stilde_flux_D0_right.h"
#include "RHSs/calculate_Stilde_flux_D0_left.h"
#include "RHSs/calculate_Stilde_flux_D1_right.h"
#include "RHSs/calculate_Stilde_flux_D1_left.h"
#include "RHSs/calculate_Stilde_flux_D2_right.h"
#include "RHSs/calculate_Stilde_flux_D2_left.h"
#include "boundary_conditions/GiRaFFE_boundary_conditions.h"
#include "A2B/driver_AtoB.h"
#include "C2P/GiRaFFE_NRPy_cons_to_prims.h"
#include "C2P/GiRaFFE_NRPy_prims_to_cons.h"
void override_BU_with_old_GiRaFFE(const paramstruct *restrict params,REAL *restrict auxevol_gfs,const int n) {
#include "set_Cparameters.h"
char filename[100];
sprintf(filename,"BU0_override-%08d.bin",n);
FILE *out2D = fopen(filename, "rb");
fread(auxevol_gfs+BU0GF*Nxx_plus_2NGHOSTS0*Nxx_plus_2NGHOSTS1*Nxx_plus_2NGHOSTS2,
sizeof(double),Nxx_plus_2NGHOSTS0*Nxx_plus_2NGHOSTS1*Nxx_plus_2NGHOSTS2,out2D);
fclose(out2D);
sprintf(filename,"BU1_override-%08d.bin",n);
out2D = fopen(filename, "rb");
fread(auxevol_gfs+BU1GF*Nxx_plus_2NGHOSTS0*Nxx_plus_2NGHOSTS1*Nxx_plus_2NGHOSTS2,
sizeof(double),Nxx_plus_2NGHOSTS0*Nxx_plus_2NGHOSTS1*Nxx_plus_2NGHOSTS2,out2D);
fclose(out2D);
sprintf(filename,"BU2_override-%08d.bin",n);
out2D = fopen(filename, "rb");
fread(auxevol_gfs+BU2GF*Nxx_plus_2NGHOSTS0*Nxx_plus_2NGHOSTS1*Nxx_plus_2NGHOSTS2,
sizeof(double),Nxx_plus_2NGHOSTS0*Nxx_plus_2NGHOSTS1*Nxx_plus_2NGHOSTS2,out2D);
fclose(out2D);
}
void GiRaFFE_NRPy_RHSs(const paramstruct *restrict params,REAL *restrict auxevol_gfs,const REAL *restrict in_gfs,REAL *restrict rhs_gfs) {
#include "set_Cparameters.h"
// First thing's first: initialize the RHSs to zero!
#pragma omp parallel for
for(int ii=0;ii<Nxx_plus_2NGHOSTS0*Nxx_plus_2NGHOSTS1*Nxx_plus_2NGHOSTS2*NUM_EVOL_GFS;ii++) {
rhs_gfs[ii] = 0.0;
}
// Next calculate the easier source terms that don't require flux directions
// This will also reset the RHSs for each gf at each new timestep.
calculate_parentheticals_for_RHSs(params,in_gfs,auxevol_gfs);
calculate_AD_gauge_psi6Phi_RHSs(params,in_gfs,auxevol_gfs,rhs_gfs);
// Now, we set up a bunch of structs of pointers to properly guide the PPM algorithm.
// They also count the number of ghostzones available.
gf_and_gz_struct in_prims[NUM_RECONSTRUCT_GFS], out_prims_r[NUM_RECONSTRUCT_GFS], out_prims_l[NUM_RECONSTRUCT_GFS];
int which_prims_to_reconstruct[NUM_RECONSTRUCT_GFS],num_prims_to_reconstruct;
const int Nxxp2NG012 = Nxx_plus_2NGHOSTS0*Nxx_plus_2NGHOSTS1*Nxx_plus_2NGHOSTS2;
REAL *temporary = auxevol_gfs + Nxxp2NG012*AEVOLPARENGF; //We're not using this anymore
// This sets pointers to the portion of auxevol_gfs containing the relevant gridfunction.
int ww=0;
in_prims[ww].gf = auxevol_gfs + Nxxp2NG012*VALENCIAVU0GF;
out_prims_r[ww].gf = auxevol_gfs + Nxxp2NG012*VALENCIAV_RU0GF;
out_prims_l[ww].gf = auxevol_gfs + Nxxp2NG012*VALENCIAV_LU0GF;
ww++;
in_prims[ww].gf = auxevol_gfs + Nxxp2NG012*VALENCIAVU1GF;
out_prims_r[ww].gf = auxevol_gfs + Nxxp2NG012*VALENCIAV_RU1GF;
out_prims_l[ww].gf = auxevol_gfs + Nxxp2NG012*VALENCIAV_LU1GF;
ww++;
in_prims[ww].gf = auxevol_gfs + Nxxp2NG012*VALENCIAVU2GF;
out_prims_r[ww].gf = auxevol_gfs + Nxxp2NG012*VALENCIAV_RU2GF;
out_prims_l[ww].gf = auxevol_gfs + Nxxp2NG012*VALENCIAV_LU2GF;
ww++;
in_prims[ww].gf = auxevol_gfs + Nxxp2NG012*BU0GF;
out_prims_r[ww].gf = auxevol_gfs + Nxxp2NG012*B_RU0GF;
out_prims_l[ww].gf = auxevol_gfs + Nxxp2NG012*B_LU0GF;
ww++;
in_prims[ww].gf = auxevol_gfs + Nxxp2NG012*BU1GF;
out_prims_r[ww].gf = auxevol_gfs + Nxxp2NG012*B_RU1GF;
out_prims_l[ww].gf = auxevol_gfs + Nxxp2NG012*B_LU1GF;
ww++;
in_prims[ww].gf = auxevol_gfs + Nxxp2NG012*BU2GF;
out_prims_r[ww].gf = auxevol_gfs + Nxxp2NG012*B_RU2GF;
out_prims_l[ww].gf = auxevol_gfs + Nxxp2NG012*B_LU2GF;
ww++;
// Prims are defined AT ALL GRIDPOINTS, so we set the # of ghostzones to zero:
for(int i=0;i<NUM_RECONSTRUCT_GFS;i++) for(int j=1;j<=3;j++) { in_prims[i].gz_lo[j]=0; in_prims[i].gz_hi[j]=0; }
// Left/right variables are not yet defined, yet we set the # of gz's to zero by default:
for(int i=0;i<NUM_RECONSTRUCT_GFS;i++) for(int j=1;j<=3;j++) { out_prims_r[i].gz_lo[j]=0; out_prims_r[i].gz_hi[j]=0; }
for(int i=0;i<NUM_RECONSTRUCT_GFS;i++) for(int j=1;j<=3;j++) { out_prims_l[i].gz_lo[j]=0; out_prims_l[i].gz_hi[j]=0; }
ww=0;
which_prims_to_reconstruct[ww]=VX; ww++;
which_prims_to_reconstruct[ww]=VY; ww++;
which_prims_to_reconstruct[ww]=VZ; ww++;
which_prims_to_reconstruct[ww]=BX; ww++;
which_prims_to_reconstruct[ww]=BY; ww++;
which_prims_to_reconstruct[ww]=BZ; ww++;
num_prims_to_reconstruct=ww;
// In each direction, perform the PPM reconstruction procedure.
// Then, add the fluxes to the RHS as appropriate.
for(int flux_dirn=0;flux_dirn<3;flux_dirn++) {
// In each direction, interpolate the metric gfs (gamma,beta,alpha) to cell faces.
interpolate_metric_gfs_to_cell_faces(params,auxevol_gfs,flux_dirn+1);
// Then, reconstruct the primitive variables on the cell faces.
// This function is housed in the file: "reconstruct_set_of_prims_PPM_GRFFE_NRPy.c"
reconstruct_set_of_prims_PPM_GRFFE_NRPy(params, auxevol_gfs, flux_dirn+1, num_prims_to_reconstruct,
which_prims_to_reconstruct, in_prims, out_prims_r, out_prims_l, temporary);
// For example, if flux_dirn==0, then at gamma_faceDD00(i,j,k) represents gamma_{xx}
// at (i-1/2,j,k), Valenciav_lU0(i,j,k) is the x-component of the velocity at (i-1/2-epsilon,j,k),
// and Valenciav_rU0(i,j,k) is the x-component of the velocity at (i-1/2+epsilon,j,k).
if(flux_dirn==0) {
// Next, we calculate the source term for StildeD. Again, this also resets the rhs_gfs array at
// each new timestep.
calculate_StildeD0_source_term(params,auxevol_gfs,rhs_gfs);
// Now, compute the electric field on each face of a cell and add it to the RHSs as appropriate
//calculate_E_field_D0_right(params,auxevol_gfs,rhs_gfs);
//calculate_E_field_D0_left(params,auxevol_gfs,rhs_gfs);
calculate_E_field_flat_all_in_one(params,auxevol_gfs,rhs_gfs,flux_dirn);
// Finally, we calculate the flux of StildeD and add the appropriate finite-differences
// to the RHSs.
calculate_Stilde_flux_D0_right(params,auxevol_gfs,rhs_gfs);
calculate_Stilde_flux_D0_left(params,auxevol_gfs,rhs_gfs);
}
else if(flux_dirn==1) {
calculate_StildeD1_source_term(params,auxevol_gfs,rhs_gfs);
//calculate_E_field_D1_right(params,auxevol_gfs,rhs_gfs);
//calculate_E_field_D1_left(params,auxevol_gfs,rhs_gfs);
calculate_E_field_flat_all_in_one(params,auxevol_gfs,rhs_gfs,flux_dirn);
calculate_Stilde_flux_D1_right(params,auxevol_gfs,rhs_gfs);
calculate_Stilde_flux_D1_left(params,auxevol_gfs,rhs_gfs);
}
else {
calculate_StildeD2_source_term(params,auxevol_gfs,rhs_gfs);
//calculate_E_field_D2_right(params,auxevol_gfs,rhs_gfs);
//calculate_E_field_D2_left(params,auxevol_gfs,rhs_gfs);
calculate_E_field_flat_all_in_one(params,auxevol_gfs,rhs_gfs,flux_dirn);
calculate_Stilde_flux_D2_right(params,auxevol_gfs,rhs_gfs);
calculate_Stilde_flux_D2_left(params,auxevol_gfs,rhs_gfs);
}
}
}
void GiRaFFE_NRPy_post_step(const paramstruct *restrict params,REAL *xx[3],REAL *restrict auxevol_gfs,REAL *restrict evol_gfs,const int n) {
// First, apply BCs to AD and psi6Phi. Then calculate BU from AD
apply_bcs_potential(params,evol_gfs);
driver_A_to_B(params,evol_gfs,auxevol_gfs);
//override_BU_with_old_GiRaFFE(params,auxevol_gfs,n);
// Apply fixes to StildeD, then recompute the velocity at the new timestep.
// Apply the current sheet prescription to the velocities
GiRaFFE_NRPy_cons_to_prims(params,xx,auxevol_gfs,evol_gfs);
// Then, recompute StildeD to be consistent with the new velocities
//GiRaFFE_NRPy_prims_to_cons(params,auxevol_gfs,evol_gfs);
// Finally, apply outflow boundary conditions to the velocities.
apply_bcs_velocity(params,auxevol_gfs);
}
""")
def generate_everything_for_UnitTesting():
# First define hydrodynamical quantities
u4U = ixp.declarerank1("u4U", DIM=4)
rho_b, P, epsilon = sp.symbols('rho_b P epsilon', real=True)
B_tildeU = ixp.declarerank1("B_tildeU", DIM=3)
# Then ADM quantities
gammaDD = ixp.declarerank2("gammaDD", "sym01", DIM=3)
KDD = ixp.declarerank2("KDD", "sym01", DIM=3)
betaU = ixp.declarerank1("betaU", DIM=3)
alpha = sp.symbols('alpha', real=True)
# Then numerical constant
sqrt4pi = sp.symbols('sqrt4pi', real=True)
# First compute smallb4U & smallbsquared from BtildeU, which are needed
# for GRMHD stress-energy tensor T4UU and T4UD:
GRHD.compute_sqrtgammaDET(gammaDD)
GRFFE.compute_B_notildeU(GRHD.sqrtgammaDET, B_tildeU)
GRFFE.compute_smallb4U(gammaDD, betaU, alpha, u4U, GRFFE.B_notildeU,
sqrt4pi)
GRFFE.compute_smallbsquared(gammaDD, betaU, alpha, GRFFE.smallb4U)
# Then compute the GRMHD stress-energy tensor:
compute_GRMHD_T4UU(gammaDD, betaU, alpha, rho_b, P, epsilon, u4U,
GRFFE.smallb4U, GRFFE.smallbsquared)
compute_GRMHD_T4UD(gammaDD, betaU, alpha, GRHDT4UU, GRFFET4UU)
# Compute conservative variables in terms of primitive variables
global rho_star, tau_tilde, S_tildeD
GRHD.compute_rho_star(alpha, GRHD.sqrtgammaDET, rho_b, u4U)
GRHD.compute_tau_tilde(alpha, GRHD.sqrtgammaDET, T4UU, GRHD.rho_star)
GRHD.compute_S_tildeD(alpha, GRHD.sqrtgammaDET, T4UD)
rho_star = GRHD.rho_star
tau_tilde = GRHD.tau_tilde
S_tildeD = GRHD.S_tildeD
# Then compute v^i from u^mu
GRHD.compute_vU_from_u4U__no_speed_limit(u4U)
# Next compute fluxes of conservative variables
global rho_star_fluxU, tau_tilde_fluxU, S_tilde_fluxUD
GRHD.compute_rho_star_fluxU(GRHD.vU, GRHD.rho_star)
GRHD.compute_tau_tilde_fluxU(alpha, GRHD.sqrtgammaDET, GRHD.vU, T4UU,
GRHD.rho_star)
GRHD.compute_S_tilde_fluxUD(alpha, GRHD.sqrtgammaDET, T4UD)
rho_star_fluxU = GRHD.rho_star_fluxU
tau_tilde_fluxU = GRHD.tau_tilde_fluxU
S_tilde_fluxUD = GRHD.S_tilde_fluxUD
# Then declare derivatives & compute g4DD_zerotimederiv_dD
gammaDD_dD = ixp.declarerank3("gammaDD_dD", "sym01", DIM=3)
betaU_dD = ixp.declarerank2("betaU_dD", "nosym", DIM=3)
alpha_dD = ixp.declarerank1("alpha_dD", DIM=3)
GRHD.compute_g4DD_zerotimederiv_dD(gammaDD, betaU, alpha, gammaDD_dD,
betaU_dD, alpha_dD)
# Then compute source terms on tau_tilde and S_tilde equations
global s_source_term, S_tilde_source_termD
GRHD.compute_s_source_term(KDD, betaU, alpha, GRHD.sqrtgammaDET, alpha_dD,
T4UU)
GRHD.compute_S_tilde_source_termD(alpha, GRHD.sqrtgammaDET,
GRHD.g4DD_zerotimederiv_dD, T4UU)
s_source_term = GRHD.s_source_term
S_tilde_source_termD = GRHD.S_tilde_source_termD
def WeylScalars_Cartesian():
# Step 3.a: Set spatial dimension (must be 3 for BSSN)
DIM = 3
par.set_parval_from_str("grid::DIM", DIM)
# Step 3.b: declare the additional gridfunctions (i.e., functions whose values are declared
# at every grid point, either inside or outside of our SymPy expressions) needed
# for this thorn:
# * the physical metric $\gamma_{ij}$,
# * the extrinsic curvature $K_{ij}$,
# * the real and imaginary components of $\psi_4$, and
# * the Weyl curvature invariants:
gammaDD = ixp.register_gridfunctions_for_single_rank2(
"AUX", "gammaDD", "sym01") # The AUX or EVOL designation is *not*
# used in diagnostic modules.
kDD = ixp.register_gridfunctions_for_single_rank2("AUX", "kDD", "sym01")
x, y, z = gri.register_gridfunctions("AUX", ["x", "y", "z"])
global psi4r, psi4i, psi3r, psi3i, psi2r, psi2i, psi1r, psi1i, psi0r, psi0i
psi4r, psi4i, psi3r, psi3i, psi2r, psi2i, psi1r, psi1i, psi0r, psi0i = gri.register_gridfunctions(
"AUX", [
"psi4r", "psi4i", "psi3r", "psi3i", "psi2r", "psi2i", "psi1r",
"psi1i", "psi0r", "psi0i"
])
# Step 4: Set which tetrad is used; at the moment, only one supported option
# The tetrad depends in general on the inverse 3-metric gammaUU[i][j]=\gamma^{ij}
# and the determinant of the 3-metric (detgamma), which are defined in
# the following line of code from gammaDD[i][j]=\gamma_{ij}.
tmpgammaUU, detgamma = ixp.symm_matrix_inverter3x3(gammaDD)
detgamma = sp.simplify(detgamma)
gammaUU = ixp.zerorank2()
for i in range(3):
for j in range(3):
gammaUU[i][j] = sp.simplify(tmpgammaUU[i][j])
if par.parval_from_str("WeylScal4NRPy.WeylScalars_Cartesian::TetradChoice"
) == "Approx_QuasiKinnersley":
# Eqs 5.6 in https://arxiv.org/pdf/gr-qc/0104063.pdf
xmoved = x # - xorig
ymoved = y # - yorig
zmoved = z # - zorig
# Step 5.a: Choose 3 orthogonal vectors. Here, we choose one in the azimuthal
# direction, one in the radial direction, and the cross product of the two.
# Eqs 5.7
v1U = ixp.zerorank1()
v2U = ixp.zerorank1()
v3U = ixp.zerorank1()
v1U[0] = -ymoved
v1U[1] = xmoved # + offset
v1U[2] = sp.sympify(0)
v2U[0] = xmoved # + offset
v2U[1] = ymoved
v2U[2] = zmoved
LeviCivitaSymbol_rank3 = ixp.LeviCivitaSymbol_dim3_rank3()
for a in range(DIM):
for b in range(DIM):
for c in range(DIM):
for d in range(DIM):
v3U[a] += sp.sqrt(
detgamma) * gammaUU[a][d] * LeviCivitaSymbol_rank3[
d][b][c] * v1U[b] * v2U[c]
for a in range(DIM):
v3U[a] = sp.simplify(v3U[a])
# Step 5.b: Gram-Schmidt orthonormalization of the vectors.
# The w_i^a vectors here are used to temporarily hold values on the way to the final vectors e_i^a
# e_1^a &= \frac{v_1^a}{\omega_{11}}
# e_2^a &= \frac{v_2^a - \omega_{12} e_1^a}{\omega_{22}}
# e_3^a &= \frac{v_3^a - \omega_{13} e_1^a - \omega_{23} e_2^a}{\omega_{33}},
# Normalize the first vector
w1U = ixp.zerorank1()
for a in range(DIM):
w1U[a] = v1U[a]
omega11 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega11 += w1U[a] * w1U[b] * gammaDD[a][b]
e1U = ixp.zerorank1()
for a in range(DIM):
e1U[a] = w1U[a] / sp.sqrt(omega11)
# Subtract off the portion of the first vector along the second, then normalize
omega12 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega12 += e1U[a] * v2U[b] * gammaDD[a][b]
w2U = ixp.zerorank1()
for a in range(DIM):
w2U[a] = v2U[a] - omega12 * e1U[a]
omega22 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega22 += w2U[a] * w2U[b] * gammaDD[a][b]
e2U = ixp.zerorank1()
for a in range(DIM):
e2U[a] = w2U[a] / sp.sqrt(omega22)
# Subtract off the portion of the first and second vectors along the third, then normalize
omega13 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega13 += e1U[a] * v3U[b] * gammaDD[a][b]
omega23 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega23 += e2U[a] * v3U[b] * gammaDD[a][b]
w3U = ixp.zerorank1()
for a in range(DIM):
w3U[a] = v3U[a] - omega13 * e1U[a] - omega23 * e2U[a]
omega33 = sp.sympify(0)
for a in range(DIM):
for b in range(DIM):
omega33 += w3U[a] * w3U[b] * gammaDD[a][b]
e3U = ixp.zerorank1()
for a in range(DIM):
e3U[a] = w3U[a] / sp.sqrt(omega33)
# Step 5.c: Construct the tetrad itself.
# Eqs. 5.6:
# l^a &= \frac{1}{\sqrt{2}} e_2^a \\
# n^a &= -\frac{1}{\sqrt{2}} e_2^a \\
# m^a &= \frac{1}{\sqrt{2}} (e_3^a + i e_1^a) \\
# \overset{*}{m}{}^a &= \frac{1}{\sqrt{2}} (e_3^a - i e_1^a)
isqrt2 = 1 / sp.sqrt(2)
ltetU = ixp.zerorank1()
ntetU = ixp.zerorank1()
# mtetU = ixp.zerorank1()
# mtetccU = ixp.zerorank1()
remtetU = ixp.zerorank1(
) # SymPy did not like trying to take the real/imaginary parts of such a
immtetU = ixp.zerorank1(
) # complicated expression, so we do it ourselves.
for i in range(DIM):
ltetU[i] = isqrt2 * e2U[i]
ntetU[i] = -isqrt2 * e2U[i]
remtetU[i] = isqrt2 * e3U[i]
immtetU[i] = isqrt2 * e1U[i]
nn = isqrt2
else:
print("Error: TetradChoice == " + par.parval_from_str("TetradChoice") +
" unsupported!")
sys.exit(1)
# Step 5: Declare and construct the second derivative of the metric.
gammaDD_dD = ixp.declarerank3("gammaDD_dD", "sym01")
# Define the Christoffel symbols
GammaUDD = ixp.zerorank3(DIM)
for i in range(DIM):
for k in range(DIM):
for l in range(DIM):
for m in range(DIM):
GammaUDD[i][k][l] += (sp.Rational(1, 2)) * gammaUU[i][m] * \
(gammaDD_dD[m][k][l] + gammaDD_dD[m][l][k] - gammaDD_dD[k][l][m])
# Step 6.a: Declare and construct the Riemann curvature tensor:
# R_{abcd} = \frac{1}{2} (\gamma_{ad,cb}+\gamma_{bc,da}-\gamma_{ac,bd}-\gamma_{bd,ac})
# + \gamma_{je} \Gamma^{j}_{bc}\Gamma^{e}_{ad} - \gamma_{je} \Gamma^{j}_{bd} \Gamma^{e}_{ac}
gammaDD_dDD = ixp.declarerank4("gammaDD_dDD", "sym01_sym23")
RiemannDDDD = ixp.zerorank4()
for a in range(DIM):
for b in range(DIM):
for c in range(DIM):
for d in range(DIM):
RiemannDDDD[a][b][c][d] = (gammaDD_dDD[a][d][c][b] + \
gammaDD_dDD[b][c][d][a] - \
gammaDD_dDD[a][c][b][d] - \
gammaDD_dDD[b][d][a][c]) / 2
for e in range(DIM):
for j in range(DIM):
RiemannDDDD[a][b][c][d] += gammaDD[j][e] * GammaUDD[j][b][c] * GammaUDD[e][a][d] - \
gammaDD[j][e] * GammaUDD[j][b][d] * GammaUDD[e][a][c]
# Step 6.b: We also need the extrinsic curvature tensor $K_{ij}$.
# In Cartesian coordinates, we already made the components gridfunctions.
# We will, however, need to calculate the trace of K seperately:
trK = sp.sympify(0)
for i in range(DIM):
for j in range(DIM):
trK += gammaUU[i][j] * kDD[i][j]
# Step 7: Build the formula for \psi_4.
# Gauss equation: involving the Riemann tensor and extrinsic curvature.
# GaussDDDD[i][j][k][l] =& R_{ijkl} + 2K_{i[k}K_{l]j}
GaussDDDD = ixp.zerorank4()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
for l in range(DIM):
GaussDDDD[i][j][k][l] = RiemannDDDD[i][j][k][
l] + kDD[i][k] * kDD[l][j] - kDD[i][l] * kDD[k][j]
# Codazzi equation: involving partial derivatives of the extrinsic curvature.
# We will first need to declare derivatives of kDD
# CodazziDDD[j][k][l] =& -2 (K_{j[k,l]} + \Gamma^p_{j[k} K_{l]p})
kDD_dD = ixp.declarerank3("kDD_dD", "sym01")
CodazziDDD = ixp.zerorank3()
for j in range(DIM):
for k in range(DIM):
for l in range(DIM):
CodazziDDD[j][k][l] = kDD_dD[j][l][k] - kDD_dD[j][k][l]
for p in range(DIM):
CodazziDDD[j][k][l] += GammaUDD[p][j][l] * kDD[k][
p] - GammaUDD[p][j][k] * kDD[l][p]
# Another piece. While not associated with any particular equation,
# this is still useful for organizational purposes.
# RojoDD[j][l]} = & R_{jl} - K_{jp} K^p_l + KK_{jl} \\
# = & \gamma^{pd} R_{jpld} - K_{jp} K^p_l + KK_{jl}
RojoDD = ixp.zerorank2()
for j in range(DIM):
for l in range(DIM):
RojoDD[j][l] = trK * kDD[j][l]
for p in range(DIM):
for d in range(DIM):
RojoDD[j][l] += gammaUU[p][d] * RiemannDDDD[j][p][l][
d] - kDD[j][p] * gammaUU[p][d] * kDD[d][l]
# Now we can calculate $\psi_4$ itself! We assume l^0 = n^0 = \frac{1}{\sqrt{2}}
# and m^0 = \overset{*}{m}{}^0 = 0 to simplify these equations.
# We calculate the Weyl scalars as defined in https://arxiv.org/abs/gr-qc/0104063
# In terms of the above-defined quantites, the psis are defined as:
# \psi_4 =&\ (\text{GaussDDDD[i][j][k][l]}) n^i \overset{*}{m}{}^j n^k \overset{*}{m}{}^l \\
# &+2 (\text{CodazziDDD[j][k][l]}) n^{0} \overset{*}{m}{}^{j} n^k \overset{*}{m}{}^l \\
# &+ (\text{RojoDD[j][l]}) n^{0} \overset{*}{m}{}^{j} n^{0} \overset{*}{m}{}^{l}.
# \psi_3 =&\ (\text{GaussDDDD[i][j][k][l]}) l^i n^j \overset{*}{m}{}^k n^l \\
# &+ (\text{CodazziDDD[j][k][l]}) (l^{0} n^{j} \overset{*}{m}{}^k n^l - l^{j} n^{0} \overset{*}{m}{}^k n^l - l^k n^j\overset{*}{m}{}^l n^0) \\
# &- (\text{RojoDD[j][l]}) l^{0} n^{j} \overset{*}{m}{}^l n^0 - l^{j} n^{0} \overset{*}{m}{}^l n^0 \\
# \psi_2 =&\ (\text{GaussDDDD[i][j][k][l]}) l^i m^j \overset{*}{m}{}^k n^l \\
# &+ (\text{CodazziDDD[j][k][l]}) (l^{0} m^{j} \overset{*}{m}{}^k n^l - l^{j} m^{0} \overset{*}{m}{}^k n^l - l^k m^l \overset{*}{m}{}^l n^0) \\
# &- (\text{RojoDD[j][l]}) l^0 m^j \overset{*}{m}{}^l n^0 \\
# \psi_1 =&\ (\text{GaussDDDD[i][j][k][l]}) n^i l^j m^k l^l \\
# &+ (\text{CodazziDDD[j][k][l]}) (n^{0} l^{j} m^k l^l - n^{j} l^{0} m^k l^l - n^k l^l m^j l^0) \\
# &- (\text{RojoDD[j][l]}) (n^{0} l^{j} m^l l^0 - n^{j} l^{0} m^l l^0) \\
# \psi_0 =&\ (\text{GaussDDDD[i][j][k][l]}) l^i m^j l^k m^l \\
# &+2 (\text{CodazziDDD[j][k][l]}) (l^0 m^j l^k m^l + l^k m^l l^0 m^j) \\
# &+ (\text{RojoDD[j][l]}) l^0 m^j l^0 m^j. \\
psi4r = sp.sympify(0)
psi4i = sp.sympify(0)
psi3r = sp.sympify(0)
psi3i = sp.sympify(0)
psi2r = sp.sympify(0)
psi2i = sp.sympify(0)
psi1r = sp.sympify(0)
psi1i = sp.sympify(0)
psi0r = sp.sympify(0)
psi0i = sp.sympify(0)
for l in range(DIM):
for j in range(DIM):
psi4r += RojoDD[j][l] * nn * nn * (remtetU[j] * remtetU[l] -
immtetU[j] * immtetU[l])
psi4i += RojoDD[j][l] * nn * nn * (-remtetU[j] * immtetU[l] -
immtetU[j] * remtetU[l])
psi3r += -RojoDD[j][l] * nn * nn * (ntetU[j] -
ltetU[j]) * remtetU[l]
psi3i += RojoDD[j][l] * nn * nn * (ntetU[j] -
ltetU[j]) * immtetU[l]
psi2r += -RojoDD[j][l] * nn * nn * (remtetU[l] * remtetU[j] +
immtetU[j] * immtetU[l])
psi2i += -RojoDD[j][l] * nn * nn * (immtetU[l] * remtetU[j] -
remtetU[j] * immtetU[l])
psi1r += RojoDD[j][l] * nn * nn * (ntetU[j] * remtetU[l] -
ltetU[j] * remtetU[l])
psi1i += RojoDD[j][l] * nn * nn * (ntetU[j] * immtetU[l] -
ltetU[j] * immtetU[l])
psi0r += RojoDD[j][l] * nn * nn * (remtetU[j] * remtetU[l] -
immtetU[j] * immtetU[l])
psi0i += RojoDD[j][l] * nn * nn * (remtetU[j] * immtetU[l] +
immtetU[j] * remtetU[l])
for l in range(DIM):
for j in range(DIM):
for k in range(DIM):
psi4r += 2 * CodazziDDD[j][k][l] * ntetU[k] * nn * (
remtetU[j] * remtetU[l] - immtetU[j] * immtetU[l])
psi4i += 2 * CodazziDDD[j][k][l] * ntetU[k] * nn * (
-remtetU[j] * immtetU[l] - immtetU[j] * remtetU[l])
psi3r += 1 * CodazziDDD[j][k][l] * nn * (
(ntetU[j] - ltetU[j]) * remtetU[k] * ntetU[l] -
remtetU[j] * ltetU[k] * ntetU[l])
psi3i += -1 * CodazziDDD[j][k][l] * nn * (
(ntetU[j] - ltetU[j]) * immtetU[k] * ntetU[l] -
immtetU[j] * ltetU[k] * ntetU[l])
psi2r += 1 * CodazziDDD[j][k][l] * nn * (
ntetU[l] *
(remtetU[j] * remtetU[k] + immtetU[j] * immtetU[k]) -
ltetU[k] *
(remtetU[j] * remtetU[l] + immtetU[j] * immtetU[l]))
psi2i += 1 * CodazziDDD[j][k][l] * nn * (
ntetU[l] *
(immtetU[j] * remtetU[k] - remtetU[j] * immtetU[k]) -
ltetU[k] *
(remtetU[j] * immtetU[l] - immtetU[j] * remtetU[l]))
psi1r += 1 * CodazziDDD[j][k][l] * nn * (
ltetU[j] * remtetU[k] * ltetU[l] - remtetU[j] * ntetU[k] *
ltetU[l] - ntetU[j] * remtetU[k] * ltetU[l])
psi1i += 1 * CodazziDDD[j][k][l] * nn * (
ltetU[j] * immtetU[k] * ltetU[l] - immtetU[j] * ntetU[k] *
ltetU[l] - ntetU[j] * immtetU[k] * ltetU[l])
psi0r += 2 * CodazziDDD[j][k][l] * nn * ltetU[k] * (
remtetU[j] * remtetU[l] - immtetU[j] * immtetU[l])
psi0i += 2 * CodazziDDD[j][k][l] * nn * ltetU[k] * (
remtetU[j] * immtetU[l] + immtetU[j] * remtetU[l])
for l in range(DIM):
for j in range(DIM):
for k in range(DIM):
for i in range(DIM):
psi4r += GaussDDDD[i][j][k][l] * ntetU[i] * ntetU[k] * (
remtetU[j] * remtetU[l] - immtetU[j] * immtetU[l])
psi4i += GaussDDDD[i][j][k][l] * ntetU[i] * ntetU[k] * (
-remtetU[j] * immtetU[l] - immtetU[j] * remtetU[l])
psi3r += GaussDDDD[i][j][k][l] * ltetU[i] * ntetU[
j] * remtetU[k] * ntetU[l]
psi3i += -GaussDDDD[i][j][k][l] * ltetU[i] * ntetU[
j] * immtetU[k] * ntetU[l]
psi2r += GaussDDDD[i][j][k][l] * ltetU[i] * ntetU[l] * (
remtetU[j] * remtetU[k] + immtetU[j] * immtetU[k])
psi2i += GaussDDDD[i][j][k][l] * ltetU[i] * ntetU[l] * (
immtetU[j] * remtetU[k] - remtetU[j] * immtetU[k])
psi1r += GaussDDDD[i][j][k][l] * ntetU[i] * ltetU[
j] * remtetU[k] * ltetU[l]
psi1i += GaussDDDD[i][j][k][l] * ntetU[i] * ltetU[
j] * immtetU[k] * ltetU[l]
psi0r += GaussDDDD[i][j][k][l] * ltetU[i] * ltetU[k] * (
remtetU[j] * remtetU[l] - immtetU[j] * immtetU[l])
psi0i += GaussDDDD[i][j][k][l] * ltetU[i] * ltetU[k] * (
remtetU[j] * immtetU[l] + immtetU[j] * remtetU[l])
def BSSN_RHSs__generate_symbolic_expressions():
######################################
# START: GENERATE SYMBOLIC EXPRESSIONS
print("Generating symbolic expressions for BSSN RHSs...")
start = time.time()
# Enable rfm_precompute infrastructure, which results in
# BSSN RHSs that are free of transcendental functions,
# even in curvilinear coordinates, so long as
# ConformalFactor is set to "W" (default).
par.set_parval_from_str("reference_metric::enable_rfm_precompute","True")
par.set_parval_from_str("reference_metric::rfm_precompute_Ccode_outdir",os.path.join(outdir,"rfm_files/"))
# Evaluate BSSN + BSSN gauge RHSs with rfm_precompute enabled:
import BSSN.BSSN_quantities as Bq
par.set_parval_from_str("BSSN.BSSN_quantities::LeaveRicciSymbolic","True")
rhs.BSSN_RHSs()
if T4UU != None:
import BSSN.BSSN_stress_energy_source_terms as Bsest
Bsest.BSSN_source_terms_for_BSSN_RHSs(T4UU)
rhs.trK_rhs += Bsest.sourceterm_trK_rhs
for i in range(3):
# Needed for Gamma-driving shift RHSs:
rhs.Lambdabar_rhsU[i] += Bsest.sourceterm_Lambdabar_rhsU[i]
# Needed for BSSN RHSs:
rhs.lambda_rhsU[i] += Bsest.sourceterm_lambda_rhsU[i]
for j in range(3):
rhs.a_rhsDD[i][j] += Bsest.sourceterm_a_rhsDD[i][j]
gaugerhs.BSSN_gauge_RHSs()
# Add Kreiss-Oliger dissipation to the BSSN RHSs:
thismodule = "KO_Dissipation"
diss_strength = par.Cparameters("REAL", thismodule, "diss_strength", default_KO_strength)
alpha_dKOD = ixp.declarerank1("alpha_dKOD")
cf_dKOD = ixp.declarerank1("cf_dKOD")
trK_dKOD = ixp.declarerank1("trK_dKOD")
betU_dKOD = ixp.declarerank2("betU_dKOD","nosym")
vetU_dKOD = ixp.declarerank2("vetU_dKOD","nosym")
lambdaU_dKOD = ixp.declarerank2("lambdaU_dKOD","nosym")
aDD_dKOD = ixp.declarerank3("aDD_dKOD","sym01")
hDD_dKOD = ixp.declarerank3("hDD_dKOD","sym01")
for k in range(3):
gaugerhs.alpha_rhs += diss_strength*alpha_dKOD[k]*rfm.ReU[k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
rhs.cf_rhs += diss_strength* cf_dKOD[k]*rfm.ReU[k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
rhs.trK_rhs += diss_strength* trK_dKOD[k]*rfm.ReU[k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
for i in range(3):
if "2ndOrder" in ShiftCondition:
gaugerhs.bet_rhsU[i] += diss_strength* betU_dKOD[i][k]*rfm.ReU[k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
gaugerhs.vet_rhsU[i] += diss_strength* vetU_dKOD[i][k]*rfm.ReU[k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
rhs.lambda_rhsU[i] += diss_strength*lambdaU_dKOD[i][k]*rfm.ReU[k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
for j in range(3):
rhs.a_rhsDD[i][j] += diss_strength*aDD_dKOD[i][j][k]*rfm.ReU[k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
rhs.h_rhsDD[i][j] += diss_strength*hDD_dKOD[i][j][k]*rfm.ReU[k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
# We use betaU as our upwinding control vector:
Bq.BSSN_basic_tensors()
betaU = Bq.betaU
# Now that we are finished with all the rfm hatted
# quantities in generic precomputed functional
# form, let's restore them to their closed-
# form expressions.
par.set_parval_from_str("reference_metric::enable_rfm_precompute","False") # Reset to False to disable rfm_precompute.
rfm.ref_metric__hatted_quantities()
par.set_parval_from_str("BSSN.BSSN_quantities::LeaveRicciSymbolic","False")
end = time.time()
print("(BENCH) Finished BSSN RHS symbolic expressions in "+str(end-start)+" seconds.")
# END: GENERATE SYMBOLIC EXPRESSIONS
######################################
BSSN_RHSs_SymbExpressions = [lhrh(lhs=gri.gfaccess("rhs_gfs","aDD00"), rhs=rhs.a_rhsDD[0][0]),
lhrh(lhs=gri.gfaccess("rhs_gfs","aDD01"), rhs=rhs.a_rhsDD[0][1]),
lhrh(lhs=gri.gfaccess("rhs_gfs","aDD02"), rhs=rhs.a_rhsDD[0][2]),
lhrh(lhs=gri.gfaccess("rhs_gfs","aDD11"), rhs=rhs.a_rhsDD[1][1]),
lhrh(lhs=gri.gfaccess("rhs_gfs","aDD12"), rhs=rhs.a_rhsDD[1][2]),
lhrh(lhs=gri.gfaccess("rhs_gfs","aDD22"), rhs=rhs.a_rhsDD[2][2]),
lhrh(lhs=gri.gfaccess("rhs_gfs","alpha"), rhs=gaugerhs.alpha_rhs),
lhrh(lhs=gri.gfaccess("rhs_gfs","betU0"), rhs=gaugerhs.bet_rhsU[0]),
lhrh(lhs=gri.gfaccess("rhs_gfs","betU1"), rhs=gaugerhs.bet_rhsU[1]),
lhrh(lhs=gri.gfaccess("rhs_gfs","betU2"), rhs=gaugerhs.bet_rhsU[2]),
lhrh(lhs=gri.gfaccess("rhs_gfs","cf"), rhs=rhs.cf_rhs),
lhrh(lhs=gri.gfaccess("rhs_gfs","hDD00"), rhs=rhs.h_rhsDD[0][0]),
lhrh(lhs=gri.gfaccess("rhs_gfs","hDD01") ,rhs=rhs.h_rhsDD[0][1]),
lhrh(lhs=gri.gfaccess("rhs_gfs","hDD02"), rhs=rhs.h_rhsDD[0][2]),
lhrh(lhs=gri.gfaccess("rhs_gfs","hDD11"), rhs=rhs.h_rhsDD[1][1]),
lhrh(lhs=gri.gfaccess("rhs_gfs","hDD12"), rhs=rhs.h_rhsDD[1][2]),
lhrh(lhs=gri.gfaccess("rhs_gfs","hDD22"), rhs=rhs.h_rhsDD[2][2]),
lhrh(lhs=gri.gfaccess("rhs_gfs","lambdaU0"),rhs=rhs.lambda_rhsU[0]),
lhrh(lhs=gri.gfaccess("rhs_gfs","lambdaU1"),rhs=rhs.lambda_rhsU[1]),
lhrh(lhs=gri.gfaccess("rhs_gfs","lambdaU2"),rhs=rhs.lambda_rhsU[2]),
lhrh(lhs=gri.gfaccess("rhs_gfs","trK"), rhs=rhs.trK_rhs),
lhrh(lhs=gri.gfaccess("rhs_gfs","vetU0"), rhs=gaugerhs.vet_rhsU[0]),
lhrh(lhs=gri.gfaccess("rhs_gfs","vetU1"), rhs=gaugerhs.vet_rhsU[1]),
lhrh(lhs=gri.gfaccess("rhs_gfs","vetU2"), rhs=gaugerhs.vet_rhsU[2]) ]
return [betaU,BSSN_RHSs_SymbExpressions]
def BSSN_constraints(add_T4UUmunu_source_terms=False):
# Step 1.a: Set spatial dimension (must be 3 for BSSN, as BSSN is
# a 3+1-dimensional decomposition of the general
# relativistic field equations)
DIM = 3
# Step 1.b: Given the chosen coordinate system, set up
# corresponding reference metric and needed
# reference metric quantities
# The following function call sets up the reference metric
# and related quantities, including rescaling matrices ReDD,
# ReU, and hatted quantities.
rfm.reference_metric()
# Step 2: Hamiltonian constraint.
# First declare all needed variables
Bq.declare_BSSN_gridfunctions_if_not_declared_already() # Sets trK
Bq.BSSN_basic_tensors() # Sets AbarDD
Bq.gammabar__inverse_and_derivs() # Sets gammabarUU
Bq.AbarUU_AbarUD_trAbar_AbarDD_dD() # Sets AbarUU and AbarDD_dD
Bq.RicciBar__gammabarDD_dHatD__DGammaUDD__DGammaU() # Sets RbarDD
Bq.phi_and_derivs() # Sets phi_dBarD & phi_dBarDD
###############################
###############################
# HAMILTONIAN CONSTRAINT
###############################
###############################
# Term 1: 2/3 K^2
global H
H = sp.Rational(2, 3) * Bq.trK**2
# Term 2: -A_{ij} A^{ij}
for i in range(DIM):
for j in range(DIM):
H += -Bq.AbarDD[i][j] * Bq.AbarUU[i][j]
# Term 3a: trace(Rbar)
Rbartrace = sp.sympify(0)
for i in range(DIM):
for j in range(DIM):
Rbartrace += Bq.gammabarUU[i][j] * Bq.RbarDD[i][j]
# Term 3b: -8 \bar{\gamma}^{ij} \bar{D}_i \phi \bar{D}_j \phi = -8*phi_dBar_times_phi_dBar
# Term 3c: -8 \bar{\gamma}^{ij} \bar{D}_i \bar{D}_j \phi = -8*phi_dBarDD_contraction
phi_dBar_times_phi_dBar = sp.sympify(0) # Term 3b
phi_dBarDD_contraction = sp.sympify(0) # Term 3c
for i in range(DIM):
for j in range(DIM):
phi_dBar_times_phi_dBar += Bq.gammabarUU[i][j] * Bq.phi_dBarD[
i] * Bq.phi_dBarD[j]
phi_dBarDD_contraction += Bq.gammabarUU[i][j] * Bq.phi_dBarDD[i][j]
# Add Term 3:
H += Bq.exp_m4phi * (Rbartrace - 8 *
(phi_dBar_times_phi_dBar + phi_dBarDD_contraction))
if add_T4UUmunu_source_terms:
M_PI = par.Cparameters("#define", thismodule, "M_PI",
"") # M_PI is pi as defined in C
BTmunu.define_BSSN_T4UUmunu_rescaled_source_terms()
rho = BTmunu.rho
H += -16 * M_PI * rho
# FIXME: ADD T4UUmunu SOURCE TERMS TO MOMENTUM CONSTRAINT!
# Step 3: M^i, the momentum constraint
###############################
###############################
# MOMENTUM CONSTRAINT
###############################
###############################
# SEE Tutorial-BSSN_constraints.ipynb for full documentation.
global MU
MU = ixp.zerorank1()
# Term 2: 6 A^{ij} \partial_j \phi:
for i in range(DIM):
for j in range(DIM):
MU[i] += 6 * Bq.AbarUU[i][j] * Bq.phi_dD[j]
# Term 3: -2/3 \bar{\gamma}^{ij} K_{,j}
trK_dD = ixp.declarerank1(
"trK_dD") # Not defined in BSSN_RHSs; only trK_dupD is defined there.
for i in range(DIM):
for j in range(DIM):
MU[i] += -sp.Rational(2, 3) * Bq.gammabarUU[i][j] * trK_dD[j]
# First define aDD_dD:
aDD_dD = ixp.declarerank3("aDD_dD", "sym01")
# Then evaluate the conformal covariant derivative \bar{D}_j \bar{A}_{lm}
AbarDD_dBarD = ixp.zerorank3()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
AbarDD_dBarD[i][j][k] = Bq.AbarDD_dD[i][j][k]
for l in range(DIM):
AbarDD_dBarD[i][j][
k] += -Bq.GammabarUDD[l][k][i] * Bq.AbarDD[l][j]
AbarDD_dBarD[i][j][
k] += -Bq.GammabarUDD[l][k][j] * Bq.AbarDD[i][l]
# Term 1: Contract twice with the metric to make \bar{D}_{j} \bar{A}^{ij}
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
for l in range(DIM):
MU[i] += Bq.gammabarUU[i][k] * Bq.gammabarUU[j][
l] * AbarDD_dBarD[k][l][j]
# Finally, we multiply by e^{-4 phi} and rescale the momentum constraint:
for i in range(DIM):
MU[i] *= Bq.exp_m4phi / rfm.ReU[i]
def VacuumMaxwellRHSs_rescaled():
global erhsU, arhsU, psi_rhs, Gamma_rhs, C, G, EU_Cart, AU_Cart
#Step 0: Set the spatial dimension parameter to 3.
par.set_parval_from_str("grid::DIM", 3)
DIM = par.parval_from_str("grid::DIM")
# Set reference metric related quantities
rfm.reference_metric()
# Register gridfunctions that are needed as input.
# Declare the rank-1 indexed expressions E^{i}, A^{i},
# and \partial^{i} \psi, that are to be evolved in time.
# Derivative variables like these must have an underscore
# in them, so the finite difference module can parse
# the variable name properly.
# e^i
eU = ixp.register_gridfunctions_for_single_rank1("EVOL", "eU")
# \partial_k ( E^i ) --> rank two tensor
eU_dD = ixp.declarerank2("eU_dD", "nosym")
# a^i
aU = ixp.register_gridfunctions_for_single_rank1("EVOL", "aU")
# \partial_k ( a^i ) --> rank two tensor
aU_dD = ixp.declarerank2("aU_dD", "nosym")
# \partial_k partial_m ( a^i ) --> rank three tensor
aU_dDD = ixp.declarerank3("aU_dDD", "sym12")
# \psi is a scalar function that is time evolved
# psi is unused here
_psi = gri.register_gridfunctions("EVOL", ["psi"])
# \Gamma is a scalar function that is time evolved
Gamma = gri.register_gridfunctions("EVOL", ["Gamma"])
# \partial_i \psi
psi_dD = ixp.declarerank1("psi_dD")
# \partial_i \Gamma
Gamma_dD = ixp.declarerank1("Gamma_dD")
# partial_i \partial_j \psi
psi_dDD = ixp.declarerank2("psi_dDD", "sym01")
ghatUU = rfm.ghatUU
GammahatUDD = rfm.GammahatUDD
GammahatUDDdD = rfm.GammahatUDDdD
ReU = rfm.ReU
ReUdD = rfm.ReUdD
ReUdDD = rfm.ReUdDD
# \partial_t a^i = -e^i - \frac{\hat{g}^{ij}\partial_j \varphi}{\text{ReU}[i]}
arhsU = ixp.zerorank1()
for i in range(DIM):
arhsU[i] -= eU[i]
for j in range(DIM):
arhsU[i] -= (ghatUU[i][j] * psi_dD[j]) / ReU[i]
# A^i
AU = ixp.zerorank1()
# \partial_k ( A^i ) --> rank two tensor
AU_dD = ixp.zerorank2()
# \partial_k partial_m ( A^i ) --> rank three tensor
AU_dDD = ixp.zerorank3()
for i in range(DIM):
AU[i] = aU[i] * ReU[i]
for j in range(DIM):
AU_dD[i][j] = aU_dD[i][j] * ReU[i] + aU[i] * ReUdD[i][j]
for k in range(DIM):
AU_dDD[i][j][k] = aU_dDD[i][j][k]*ReU[i] + aU_dD[i][j]*ReUdD[i][k] +\
aU_dD[i][k]*ReUdD[i][j] + aU[i]*ReUdDD[i][j][k]
# Term 1 = \hat{g}^{ij}\partial_j \Gamma
Term1U = ixp.zerorank1()
for i in range(DIM):
for j in range(DIM):
Term1U[i] += ghatUU[i][j] * Gamma_dD[j]
# Term 2: A^i_{,kj}
Term2UDD = ixp.zerorank3()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
Term2UDD[i][j][k] += AU_dDD[i][k][j]
# Term 3: \hat{\Gamma}^i_{mk,j} A^m + \hat{\Gamma}^i_{mk} A^m_{,j}
# + \hat{\Gamma}^i_{dj}A^d_{,k} - \hat{\Gamma}^d_{kj} A^i_{,d}
Term3UDD = ixp.zerorank3()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
for m in range(DIM):
Term3UDD[i][j][k] += GammahatUDDdD[i][m][k][j]*AU[m] \
+ GammahatUDD[i][m][k]*AU_dD[m][j] \
+ GammahatUDD[i][m][j]*AU_dD[m][k] \
- GammahatUDD[m][k][j]*AU_dD[i][m]
# Term 4: \hat{\Gamma}^i_{dj}\hat{\Gamma}^d_{mk} A^m -
# \hat{\Gamma}^d_{kj} \hat{\Gamma}^i_{md} A^m
Term4UDD = ixp.zerorank3()
for i in range(DIM):
for j in range(DIM):
for k in range(DIM):
for m in range(DIM):
for d in range(DIM):
Term4UDD[i][j][k] += ( GammahatUDD[i][d][j]*GammahatUDD[d][m][k] \
-GammahatUDD[d][k][j]*GammahatUDD[i][m][d])*AU[m]
# \partial_t E^i = \hat{g}^{ij}\partial_j \Gamma - \hat{\gamma}^{jk}*
# (A^i_{,kj}
# + \hat{\Gamma}^i_{mk,j} A^m + \hat{\Gamma}^i_{mk} A^m_{,j}
# + \hat{\Gamma}^i_{dj} A^d_{,k} - \hat{\Gamma}^d_{kj} A^i_{,d}
# + \hat{\Gamma}^i_{dj}\hat{\Gamma}^d_{mk} A^m
# - \hat{\Gamma}^d_{kj} \hat{\Gamma}^i_{md} A^m)
ErhsU = ixp.zerorank1()
for i in range(DIM):
ErhsU[i] += Term1U[i]
for j in range(DIM):
for k in range(DIM):
ErhsU[i] -= ghatUU[j][k] * (
Term2UDD[i][j][k] + Term3UDD[i][j][k] + Term4UDD[i][j][k])
erhsU = ixp.zerorank1()
for i in range(DIM):
erhsU[i] = ErhsU[i] / ReU[i]
# \partial_t \Gamma = -\hat{g}^{ij} (\partial_i \partial_j \varphi -
# \hat{\Gamma}^k_{ji} \partial_k \varphi)
Gamma_rhs = sp.sympify(0)
for i in range(DIM):
for j in range(DIM):
Gamma_rhs -= ghatUU[i][j] * psi_dDD[i][j]
for k in range(DIM):
Gamma_rhs += ghatUU[i][j] * GammahatUDD[k][j][i] * psi_dD[k]
# \partial_t \varphi = -\Gamma
psi_rhs = -Gamma
# \mathcal{G} \equiv \Gamma - \partial_i A^i + \hat{\Gamma}^i_{ji} A^j
G = Gamma
for i in range(DIM):
G -= AU_dD[i][i]
for j in range(DIM):
G += GammahatUDD[i][j][i] * AU[j]
# E^i
EU = ixp.zerorank1()
EU_dD = ixp.zerorank2()
for i in range(DIM):
EU[i] = eU[i] * ReU[i]
for j in range(DIM):
EU_dD[i][j] = eU_dD[i][j] * ReU[i] + eU[i] * ReUdD[i][j]
C = sp.sympify(0)
for i in range(DIM):
C += EU_dD[i][i]
for j in range(DIM):
C += GammahatUDD[i][j][i] * EU[j]
def Convert_to_Cartesian_basis(VU):
# Coordinate transformation from original basis to Cartesian
rfm.reference_metric()
VU_Cart = ixp.zerorank1()
Jac_dxCartU_dxOrigD = ixp.zerorank2()
for i in range(DIM):
for j in range(DIM):
Jac_dxCartU_dxOrigD[i][j] = sp.diff(rfm.xxCart[i], rfm.xx[j])
for i in range(DIM):
for j in range(DIM):
VU_Cart[i] += Jac_dxCartU_dxOrigD[i][j] * VU[j]
return VU_Cart
AU_Cart = Convert_to_Cartesian_basis(AU)
EU_Cart = Convert_to_Cartesian_basis(EU)
def BSSN_RHSs__generate_symbolic_expressions(
LapseCondition="OnePlusLog",
ShiftCondition="GammaDriving2ndOrder_Covariant",
enable_KreissOliger_dissipation=True,
enable_stress_energy_source_terms=False,
leave_Ricci_symbolic=True):
######################################
# START: GENERATE SYMBOLIC EXPRESSIONS
starttime = print_msg_with_timing("BSSN_RHSs",
msg="Symbolic",
startstop="start")
# Returns None if enable_stress_energy_source_terms==False; otherwise returns symb expressions for T4UU
T4UU = register_stress_energy_source_terms_return_T4UU(
enable_stress_energy_source_terms)
# Evaluate BSSN RHSs:
import BSSN.BSSN_quantities as Bq
par.set_parval_from_str("BSSN.BSSN_quantities::LeaveRicciSymbolic",
str(leave_Ricci_symbolic))
rhs.BSSN_RHSs()
if enable_stress_energy_source_terms:
import BSSN.BSSN_stress_energy_source_terms as Bsest
Bsest.BSSN_source_terms_for_BSSN_RHSs(T4UU)
rhs.trK_rhs += Bsest.sourceterm_trK_rhs
for i in range(3):
# Needed for Gamma-driving shift RHSs:
rhs.Lambdabar_rhsU[i] += Bsest.sourceterm_Lambdabar_rhsU[i]
# Needed for BSSN RHSs:
rhs.lambda_rhsU[i] += Bsest.sourceterm_lambda_rhsU[i]
for j in range(3):
rhs.a_rhsDD[i][j] += Bsest.sourceterm_a_rhsDD[i][j]
par.set_parval_from_str("BSSN.BSSN_gauge_RHSs::LapseEvolutionOption",
LapseCondition)
par.set_parval_from_str("BSSN.BSSN_gauge_RHSs::ShiftEvolutionOption",
ShiftCondition)
gaugerhs.BSSN_gauge_RHSs() # Can depend on above RHSs
# Restore BSSN.BSSN_quantities::LeaveRicciSymbolic to False
par.set_parval_from_str("BSSN.BSSN_quantities::LeaveRicciSymbolic",
"False")
# Add Kreiss-Oliger dissipation to the BSSN RHSs:
if enable_KreissOliger_dissipation:
thismodule = "KO_Dissipation"
diss_strength = par.Cparameters(
"REAL", thismodule, "diss_strength", 0.1
) # *Bq.cf # *Bq.cf*Bq.cf*Bq.cf # cf**1 is found better than cf**4 over the long term.
alpha_dKOD = ixp.declarerank1("alpha_dKOD")
cf_dKOD = ixp.declarerank1("cf_dKOD")
trK_dKOD = ixp.declarerank1("trK_dKOD")
betU_dKOD = ixp.declarerank2("betU_dKOD", "nosym")
vetU_dKOD = ixp.declarerank2("vetU_dKOD", "nosym")
lambdaU_dKOD = ixp.declarerank2("lambdaU_dKOD", "nosym")
aDD_dKOD = ixp.declarerank3("aDD_dKOD", "sym01")
hDD_dKOD = ixp.declarerank3("hDD_dKOD", "sym01")
for k in range(3):
gaugerhs.alpha_rhs += diss_strength * alpha_dKOD[k] * rfm.ReU[
k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
rhs.cf_rhs += diss_strength * cf_dKOD[k] * rfm.ReU[
k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
rhs.trK_rhs += diss_strength * trK_dKOD[k] * rfm.ReU[
k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
for i in range(3):
if "2ndOrder" in ShiftCondition:
gaugerhs.bet_rhsU[
i] += diss_strength * betU_dKOD[i][k] * rfm.ReU[
k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
gaugerhs.vet_rhsU[
i] += diss_strength * vetU_dKOD[i][k] * rfm.ReU[
k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
rhs.lambda_rhsU[
i] += diss_strength * lambdaU_dKOD[i][k] * rfm.ReU[
k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
for j in range(3):
rhs.a_rhsDD[i][
j] += diss_strength * aDD_dKOD[i][j][k] * rfm.ReU[
k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
rhs.h_rhsDD[i][
j] += diss_strength * hDD_dKOD[i][j][k] * rfm.ReU[
k] # ReU[k] = 1/scalefactor_orthog_funcform[k]
# We use betaU as our upwinding control vector:
Bq.BSSN_basic_tensors()
betaU = Bq.betaU
# END: GENERATE SYMBOLIC EXPRESSIONS
######################################
lhs_names = ["alpha", "cf", "trK"]
rhs_exprs = [gaugerhs.alpha_rhs, rhs.cf_rhs, rhs.trK_rhs]
for i in range(3):
lhs_names.append("betU" + str(i))
rhs_exprs.append(gaugerhs.bet_rhsU[i])
lhs_names.append("lambdaU" + str(i))
rhs_exprs.append(rhs.lambda_rhsU[i])
lhs_names.append("vetU" + str(i))
rhs_exprs.append(gaugerhs.vet_rhsU[i])
for j in range(i, 3):
lhs_names.append("aDD" + str(i) + str(j))
rhs_exprs.append(rhs.a_rhsDD[i][j])
lhs_names.append("hDD" + str(i) + str(j))
rhs_exprs.append(rhs.h_rhsDD[i][j])
# Sort the lhss list alphabetically, and rhss to match.
# This ensures the RHSs are evaluated in the same order
# they're allocated in memory:
lhs_names, rhs_exprs = [
list(x) for x in zip(
*sorted(zip(lhs_names, rhs_exprs), key=lambda pair: pair[0]))
]
# Declare the list of lhrh's
BSSN_RHSs_SymbExpressions = []
for var in range(len(lhs_names)):
BSSN_RHSs_SymbExpressions.append(
lhrh(lhs=gri.gfaccess("rhs_gfs", lhs_names[var]),
rhs=rhs_exprs[var]))
print_msg_with_timing("BSSN_RHSs",
msg="Symbolic",
startstop="stop",
starttime=starttime)
return [betaU, BSSN_RHSs_SymbExpressions]
