def eval_baryon_density(self, p):
if isinstance(p, list) or isinstance(p, np.ndarray):
rho = np.zeros(len(p))
for i, pres in enumerate(p):
rho [i] = lalsim.SimNeutronStarEOSRestMassDensityOfPseudoEnthalpy(
lalsim.SimNeutronStarEOSPseudoEnthalpyOfPressure(pres,self.eos), self.eos)
else:
rho = lalsim.SimNeutronStarEOSRestMassDensityOfPseudoEnthalpy(
lalsim.SimNeutronStarEOSPseudoEnthalpyOfPressure(p,self.eos), self.eos)
return rho
def eval_speed_of_sound(self, p):
if isinstance(p, list) or isinstance(p, np.ndarray):
cs = np.zeros(len(p))
for i, pres in enumerate(p):
try:
h = lalsim.SimNeutronStarEOSPseudoEnthalpyOfPressure(
pres, self.eos)
cs[i] = lalsim.SimNeutronStarEOSSpeedOfSound(h, self.eos)
except:
print(pres, "failed to produce a valid sound speed")
break
else:
h = lalsim.SimNeutronStarEOSPseudoEnthalpyOfPressure(p, self.eos)
cs = lalsim.SimNeutronStarEOSSpeedOfSound(h, self.eos)
return cs
def lal_inf_eos_physical_check(gammas, verbose=False):
'''
Python version of LALInferenceEOSPhysicalCheck:
https://lscsoft.docs.ligo.org/lalsuite/lalinference/_l_a_l_inference_8c_source.html#l02404
'''
# apply 0.6 < Gamma(p) < 4.5 constraint
if not lalinf_sd_gamma_check(gammas):
return False
else:
# create LAL EOS object
eos = lalsim.SimNeutronStarEOS4ParameterSpectralDecomposition(*gammas)
# ensure mass turnover doesn't happen too soon
mdat_prev = 0.0
logpmin = 75.5
logpmax = np.log(lalsim.SimNeutronStarEOSMaxPressure(eos))
dlogp = (logpmax - logpmin) / 100.0
for j in range(4):
# determine if maximum mass has been found
pdat = np.exp(logpmin + j * dlogp)
rdat, mdat, kdat = lalsim.SimNeutronStarTOVODEIntegrate(pdat, eos)
if mdat <= mdat_prev:
if verbose:
print('rejecting: too few EOS points', gammas)
return False
mdat_prev = mdat
# make EOS family, and calculate speed of sound and max
# and min mass allowed by EOS
fam = lalsim.CreateSimNeutronStarFamily(eos)
min_mass_kg = lalsim.SimNeutronStarFamMinimumMass(fam)
max_mass_kg = lalsim.SimNeutronStarMaximumMass(fam)
pmax = lalsim.SimNeutronStarCentralPressure(max_mass_kg, fam)
hmax = lalsim.SimNeutronStarEOSPseudoEnthalpyOfPressure(pmax, eos)
vsmax = lalsim.SimNeutronStarEOSSpeedOfSoundGeometerized(hmax, eos)
# apply constraints on speed of sound and maximum mass
if vsmax > c_s_max:
if verbose:
print('rejecting:', \
'sound speed {:4.2f} too high'.format(vsmax), \
gammas)
return False
if max_mass_kg < ns_mass_max_kg:
if verbose:
print('rejecting:', \
'max NS mass {:4.2f} too low'.format(max_mass_kg / m_sol_kg), \
gammas)
return False
return True
def test_speed_of_sound_causal(self,
test_only_under_mmax=True,
fast_test=True):
"""
Test if EOS satisfies speed of sound.
Relies on low-level lalsimulation interpolation routines to get v(h) and as such is not very reliable
By DEFAULT, we are testing the part of the EOS that is
- at the largest pressure (assuming monotonic sound speed)
- associated with the maximum mass NS that is stable
We can also test the full table that is provided to us.
https://git.ligo.org/lscsoft/lalsuite/blob/lalinference_o2/lalinference/src/LALInference.c#L2513
"""
npts_internal = 1000
eos = self.eos
fam = self.eos_fam
# Largest NS provides largest attained central pressure
m_max_SI = self.mMaxMsun * lal.MSUN_SI
if not test_only_under_mmax:
hmax = lalsim.SimNeutronStarEOSMaxPseudoEnthalpy(eos)
else:
try:
pmax = lalsim.SimNeutronStarCentralPressure(m_max_SI, fam)
hmax = lalsim.SimNeutronStarEOSPseudoEnthalpyOfPressure(
pmax, eos)
except:
# gatch gsl interpolation errors for example
return False
if fast_test:
# https://git.ligo.org/lscsoft/lalsuite/blob/lalinference_o2/lalinference/src/LALInference.c#L2513
try:
vsmax = lalsim.SimNeutronStarEOSSpeedOfSoundGeometerized(
hmax, eos)
return vsmax < 1.1
except:
# catch gsl interpolation errors for example
return False
else:
if rosDebug:
print(" performing comprehensive test ")
h = np.linspace(0.0001, hmax, npts_internal)
# h = np.linspace(0.0001,lalsim.SimNeutronStarEOSMinAcausalPseudoEnthalpy(eos),npts_internal)
vs_internal = np.zeros(npts_internal)
for indx in np.arange(npts_internal):
vs_internal[
indx] = lalsim.SimNeutronStarEOSSpeedOfSoundGeometerized(
h[indx], eos)
if rosDebug:
print(h[indx], vs_internal[indx])
return not np.any(
vs_internal > 1.1) # allow buffer, so we have some threshold
def is_causal(self):
p_max = lalsim.SimNeutronStarEOSMaxPressure(self.eos)
c_s_max = lalsim.SimNeutronStarEOSSpeedOfSound(
lalsim.SimNeutronStarEOSPseudoEnthalpyOfPressure(p_max, self.eos),
self.eos)
return c_s_max < c / 100 * 1.1 # Conversion from cgs to SI (leave some leeway like in 1805.11217)