def is_consistent(self,k):
r"""
Return True if the Weil representation is a multiplier of weight k.
"""
if self._verbose>0:
print "is_consistent at wr! k={0}".format(k)
twok =QQ(2)*QQ(k)
if not twok.is_integral():
return False
if self._sym_type <>0:
if self.is_dual():
sig_mod_4 = -self._weil_module.signature() % 4
else:
sig_mod_4 = self._weil_module.signature() % 4
if is_odd(self._weil_module.signature()):
return (twok % 4 == (self._sym_type*sig_mod_4 %4))
else:
if sig_mod_4 == (1 - self._sym_type) % 4:
return twok % 4 == 0
else:
return twok % 4 == 2
if is_even(twok) and is_even(self._weil_module.signature()):
return True
if is_odd(twok) and is_odd(self._weil_module.signature()):
return True
return False
def is_consistent(self, k):
r"""
Return True if the Weil representation is a multiplier of weight k.
"""
if self._verbose > 0:
print("is_consistent at wr! k={0}".format(k))
twok = QQ(2) * QQ(k)
if not twok.is_integral():
return False
if self._sym_type != 0:
if self.is_dual():
sig_mod_4 = -self._weil_module.signature() % 4
else:
sig_mod_4 = self._weil_module.signature() % 4
if is_odd(self._weil_module.signature()):
return (twok % 4 == (self._sym_type * sig_mod_4 % 4))
else:
if sig_mod_4 == (1 - self._sym_type) % 4:
return twok % 4 == 0
else:
return twok % 4 == 2
if is_even(twok) and is_even(self._weil_module.signature()):
return True
if is_odd(twok) and is_odd(self._weil_module.signature()):
return True
return False
def __init__(self,WR,weight=QQ(1)/QQ(2),use_symmetry=True,group=SL2Z,dual=False,**kwargs):
r"""
WR should be a Weil representation.
INPUT:
- weight -- weight (should be consistent with the signature of self)
- use_symmetry -- if False we do not symmetrize the functions with respect to Z
-- if True we need a compatible weight
- 'group' -- Group to act on.
"""
if isinstance(WR,(Integer,int)):
#self.WR=WeilRepDiscriminantForm(WR)
#self.WR=WeilModule(WR)
self._weil_module = WeilModule(WR)
elif hasattr(WR,"signature"):
self._weil_module=WR
else:
raise ValueError,"{0} is not a Weil module!".format(WR)
self._sym_type = 0
if group.level() <>1:
raise NotImplementedError,"Only Weil representations of SL2Z implemented!"
self._group = MySubgroup(Gamma0(1))
self._dual = int(dual)
self._sgn = (-1)**self._dual
self.Qv=[]
self._weight = weight
self._use_symmetry = use_symmetry
self._kwargs = kwargs
self._sgn = (-1)**int(dual)
half = QQ(1)/QQ(2)
threehalf = QQ(3)/QQ(2)
if use_symmetry:
## First find weight mod 2:
twok= QQ(2)*QQ(weight)
if not twok.is_integral():
raise ValueError,"Only integral or half-integral weights implemented!"
kmod2 = QQ(twok % 4)/QQ(2)
if dual:
sig_mod_4 = -self._weil_module.signature() % 4
else:
sig_mod_4 = self._weil_module.signature() % 4
sym_type = 0
if (kmod2,sig_mod_4) in [(half,1),(threehalf,3),(0,0),(1,2)]:
sym_type = 1
elif (kmod2,sig_mod_4) in [(half,3),(threehalf,1),(0,2),(1,0)]:
sym_type = -1
else:
raise ValueError,"The Weil module with signature {0} is incompatible with the weight {1}!".format( self._weil_module.signature(),weight)
## Deven and Dodd contains the indices for the even and odd basis
Deven=[]; Dodd=[]
if sym_type==1:
self._D = self._weil_module.even_submodule(indices=1)
else: #sym_type==-1:
self._D = self._weil_module.odd_submodule(indices=1)
self._sym_type=sym_type
dim = len(self._D) #Dfinish-Dstart+1
else:
dim = len(self._weil_module.finite_quadratic_module().list())
self._D = range(dim)
self._sym_type=0
if hasattr(self._weil_module,"finite_quadratic_module"):
# for x in list(self._weil_module.finite_quadratic_module()):
for x in self._weil_module.finite_quadratic_module():
self.Qv.append(self._weil_module.finite_quadratic_module().Q(x))
else:
self.Qv=self._weil_module.Qv
ambient_rank = self._weil_module.rank()
MultiplierSystem.__init__(self,self._group,dual=dual,dimension=dim,ambient_rank=ambient_rank)
def __init__(self,
WR,
weight=QQ(1) / QQ(2),
use_symmetry=True,
group=SL2Z,
dual=False,
**kwargs):
r"""
WR should be a Weil representation.
INPUT:
- weight -- weight (should be consistent with the signature of self)
- use_symmetry -- if False we do not symmetrize the functions with respect to Z
-- if True we need a compatible weight
- 'group' -- Group to act on.
"""
if isinstance(WR, (Integer, int)):
#self.WR=WeilRepDiscriminantForm(WR)
#self.WR=WeilModule(WR)
self._weil_module = WeilModule(WR)
elif hasattr(WR, "signature"):
self._weil_module = WR
else:
raise ValueError("{0} is not a Weil module!".format(WR))
self._sym_type = 0
if group.level() != 1:
raise NotImplementedError(
"Only Weil representations of SL2Z implemented!")
self._group = MySubgroup(Gamma0(1))
self._dual = int(dual)
self._sgn = (-1)**self._dual
self.Qv = []
self._weight = weight
self._use_symmetry = use_symmetry
self._kwargs = kwargs
self._sgn = (-1)**int(dual)
half = QQ(1) / QQ(2)
threehalf = QQ(3) / QQ(2)
if use_symmetry:
## First find weight mod 2:
twok = QQ(2) * QQ(weight)
if not twok.is_integral():
raise ValueError(
"Only integral or half-integral weights implemented!")
kmod2 = QQ(twok % 4) / QQ(2)
if dual:
sig_mod_4 = -self._weil_module.signature() % 4
else:
sig_mod_4 = self._weil_module.signature() % 4
sym_type = 0
if (kmod2, sig_mod_4) in [(half, 1), (threehalf, 3), (0, 0),
(1, 2)]:
sym_type = 1
elif (kmod2, sig_mod_4) in [(half, 3), (threehalf, 1), (0, 2),
(1, 0)]:
sym_type = -1
else:
raise ValueError(
"The Weil module with signature {0} is incompatible with the weight {1}!"
.format(self._weil_module.signature(), weight))
## Deven and Dodd contains the indices for the even and odd basis
Deven = []
Dodd = []
if sym_type == 1:
self._D = self._weil_module.even_submodule(indices=1)
else: #sym_type==-1:
self._D = self._weil_module.odd_submodule(indices=1)
self._sym_type = sym_type
dim = len(self._D) #Dfinish-Dstart+1
else:
dim = len(self._weil_module.finite_quadratic_module().list())
self._D = list(range(dim))
self._sym_type = 0
if hasattr(self._weil_module, "finite_quadratic_module"):
# for x in list(self._weil_module.finite_quadratic_module()):
for x in self._weil_module.finite_quadratic_module():
self.Qv.append(
self._weil_module.finite_quadratic_module().Q(x))
else:
self.Qv = self._weil_module.Qv
ambient_rank = self._weil_module.rank()
MultiplierSystem.__init__(self,
self._group,
dual=dual,
dimension=dim,
ambient_rank=ambient_rank)
