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schemes/hyperelliptic_curves/hyperelliptic_padic_field.py (browse directory)
"""
Hyperelliptic curves over a padic field.
"""
#*****************************************************************************
# Copyright (C) 2007 Robert Bradshaw <robertwb@math.washington.edu>
# Distributed under the terms of the GNU General Public License (GPL)
# http://www.gnu.org/licenses/
#*****************************************************************************
import hyperelliptic_generic
from sage.rings.all import PowerSeriesRing, PolynomialRing, ZZ, QQ, O, pAdicField, GF, RR, RationalField, Infinity
from sage.misc.functional import log
from sage.modules.free_module import VectorSpace
from sage.matrix.constructor import matrix
from sage.modules.all import vector
class HyperellipticCurve_padic_field(hyperelliptic_generic.HyperellipticCurve_generic):
# The functions below were prototyped at the 2007 Arizona Winter School by
# Robert Bradshaw and Ralf Gerkmann, working with Miljan Brakovevic and
# Kiran Kedlaya
# All of the below is with respect to the Monsky Washnitzer cohomology.
def local_analytic_interpolation(self, P, Q):
"""
For points $P$, $Q$ in the same residue disc,
this constructs an interpolation from $P$ to $Q$
(in homogeneous coordinates) in a power series in
the local parameter $t$, with precision equal to
the $p$-adic precision of the underlying ring.
INPUT:
- P and Q points on self in the same residue disc
OUTPUT:
Returns a point $X(t) = ( x(t) : y(t) : z(t) )$ such that
(1) $X(0) = P$ and $X(1) = Q$ if $P, Q$ are not in the infinite disc
(2) $X(P[0]^g}/P[1]) = P$ and $X(Q[0]^g/Q[1]) = Q$ if $P, Q$ are in the infinite disc
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,8)
sage: HK = H.change_ring(K)
A non-Weierstrass disc::
sage: P = HK(0,3)
sage: Q = HK(5, 3 + 3*5^2 + 2*5^3 + 3*5^4 + 2*5^5 + 2*5^6 + 3*5^7 + O(5^8))
sage: x,y,z, = HK.local_analytic_interpolation(P,Q)
sage: x(0) == P[0], x(1) == Q[0], y(0) == P[1], y(1) == Q[1]
(True, True, True, True)
A finite Weierstrass disc::
sage: P = HK.lift_x(1 + 2*5^2)
sage: Q = HK.lift_x(1 + 3*5^2)
sage: x,y,z = HK.local_analytic_interpolation(P,Q)
sage: x(0) == P[0], x(1) == Q[0], y(0) == P[1], y(1) == Q[1]
(True, True, True, True)
The infinite disc::
sage: P = HK.lift_x(5^-2)
sage: Q = HK.lift_x(4*5^-2)
sage: x,y,z = HK.local_analytic_interpolation(P,Q)
sage: x = x/z
sage: y = y/z
sage: x(P[0]/P[1]) == P[0]
True
sage: x(Q[0]/Q[1]) == Q[0]
True
sage: y(P[0]/P[1]) == P[1]
True
sage: y(Q[0]/Q[1]) == Q[1]
True
An error if points are not in the same disc::
sage: x,y,z = HK.local_analytic_interpolation(P,HK(1,0))
Traceback (most recent call last):
...
ValueError: (5^-2 + O(5^6) : 5^-3 + 4*5^2 + 5^3 + 3*5^4 + O(5^5) : 1 + O(5^8)) and (1 + O(5^8) : 0 : 1 + O(5^8)) are not in the same residue disc
AUTHORS:
- Robert Bradshaw (2007-03)
- Jennifer Balakrishnan (2010-02)
"""
prec = self.base_ring().precision_cap()
if self.is_same_disc(P,Q) == False:
raise ValueError, "%s and %s are not in the same residue disc"%(P,Q)
disc = self.residue_disc(P)
t = PowerSeriesRing(self.base_ring(), 't', prec).gen(0)
if disc == self.change_ring(self.base_ring().residue_field())(0,1,0):
x,y = self.local_coordinates_at_infinity(2*prec)
g = self.genus()
return (x*t**(2*g+1),y*t**(2*g+1),t**(2*g+1))
if disc[1] !=0:
x = P[0]+t*(Q[0]-P[0])
pts = self.lift_x(x, all=True)
if pts[0][1][0] == P[1]:
return pts[0]
else:
return pts[1]
else:
S = self.find_char_zero_weier_point(P)
x,y = self.local_coord(S)
a = P[1]
b = Q[1] - P[1]
y = a + b*t
x = x(y)
return (x, y, 1)
def weierstrass_points(self):
"""
Return the Weierstrass points of self defined over self.base_ring(),
that is, the point at infinity and those points in the support
of the divisor of $y$
EXAMPLES::
sage: K = pAdicField(11, 5)
sage: x = polygen(K)
sage: C = HyperellipticCurve(x^5 + 33/16*x^4 + 3/4*x^3 + 3/8*x^2 - 1/4*x + 1/16)
sage: C.weierstrass_points()
[(0 : 1 + O(11^5) : 0), (7 + 10*11 + 4*11^3 + O(11^5) : 0 : 1 + O(11^5))]
"""
f, h = self.hyperelliptic_polynomials()
if h != 0:
raise NotImplementedError()
return [self((0,1,0))] + [self((x, 0, 1)) for x in f.roots()]
def is_in_weierstrass_disc(self,P):
"""
Checks if $P$ is in a Weierstrass disc
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,8)
sage: HK = H.change_ring(K)
sage: P = HK(0,3)
sage: HK.is_in_weierstrass_disc(P)
False
sage: Q = HK(0,1,0)
sage: HK.is_in_weierstrass_disc(Q)
True
sage: S = HK(1,0)
sage: HK.is_in_weierstrass_disc(S)
True
sage: T = HK.lift_x(1+3*5^2); T
(1 + 3*5^2 + O(5^8) : 2*5 + 4*5^3 + 3*5^4 + 5^5 + 3*5^6 + O(5^7) : 1 + O(5^8))
sage: HK.is_in_weierstrass_disc(T)
True
AUTHOR:
- Jennifer Balakrishnan (2010-02)
"""
if (P[1].valuation() == 0 and P != self(0,1,0)):
return False
else:
return True
def is_weierstrass(self,P):
"""
Checks if $P$ is a Weierstrass point (i.e., fixed by the hyperelliptic involution)
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,8)
sage: HK = H.change_ring(K)
sage: P = HK(0,3)
sage: HK.is_weierstrass(P)
False
sage: Q = HK(0,1,0)
sage: HK.is_weierstrass(Q)
True
sage: S = HK(1,0)
sage: HK.is_weierstrass(S)
True
sage: T = HK.lift_x(1+3*5^2); T
(1 + 3*5^2 + O(5^8) : 2*5 + 4*5^3 + 3*5^4 + 5^5 + 3*5^6 + O(5^7) : 1 + O(5^8))
sage: HK.is_weierstrass(T)
False
AUTHOR:
- Jennifer Balakrishnan (2010-02)
"""
if (P[1] == 0 or P[2] ==0):
return True
else:
return False
def find_char_zero_weier_point(self, Q):
"""
Given $Q$ a point on self in a Weierstrass disc, finds the
center of the Weierstrass disc (if defined over self.base_ring())
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,8)
sage: HK = H.change_ring(K)
sage: P = HK.lift_x(1 + 2*5^2)
sage: Q = HK.lift_x(5^-2)
sage: S = HK(1,0)
sage: T = HK(0,1,0)
sage: HK.find_char_zero_weier_point(P)
(1 + O(5^8) : 0 : 1 + O(5^8))
sage: HK.find_char_zero_weier_point(Q)
(0 : 1 + O(5^8) : 0)
sage: HK.find_char_zero_weier_point(S)
(1 + O(5^8) : 0 : 1 + O(5^8))
sage: HK.find_char_zero_weier_point(T)
(0 : 1 + O(5^8) : 0)
AUTHOR:
- Jennifer Balakrishnan
"""
if self.is_in_weierstrass_disc(Q) == False:
raise ValueError, "%s is not in a Weierstrass disc"%Q
points = self.weierstrass_points()
for P in points:
if self.is_same_disc(P,Q):
return P
def residue_disc(self,P):
"""
Gives the residue disc of $P$
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,8)
sage: HK = H.change_ring(K)
sage: P = HK.lift_x(1 + 2*5^2)
sage: HK.residue_disc(P)
(1 : 0 : 1)
sage: Q = HK(0,3)
sage: HK.residue_disc(Q)
(0 : 3 : 1)
sage: S = HK.lift_x(5^-2)
sage: HK.residue_disc(S)
(0 : 1 : 0)
sage: T = HK(0,1,0)
sage: HK.residue_disc(T)
(0 : 1 : 0)
AUTHOR:
- Jennifer Balakrishnan
"""
xPv = P[0].valuation()
yPv = P[1].valuation()
F = self.base_ring().residue_field()
HF = self.change_ring(F)
if P == self(0,1,0):
return HF(0,1,0)
elif yPv > 0:
if xPv > 0:
return HF(0,0,1)
if xPv == 0:
return HF(P[0].list()[0], 0,1)
elif yPv ==0:
if xPv > 0:
return HF(0, P[1].list()[0],1)
if xPv == 0:
return HF(P[0].list()[0], P[1].list()[0],1)
else:
return HF(0,1,0)
def is_same_disc(self,P,Q):
"""
Checks if $P,Q$ are in same residue disc
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,8)
sage: HK = H.change_ring(K)
sage: P = HK.lift_x(1 + 2*5^2)
sage: Q = HK.lift_x(5^-2)
sage: S = HK(1,0)
sage: HK.is_same_disc(P,Q)
False
sage: HK.is_same_disc(P,S)
True
sage: HK.is_same_disc(Q,S)
False
"""
if self.residue_disc(P) == self.residue_disc(Q):
return True
else:
return False
def tiny_integrals(self, F, P, Q):
r"""
Evaluate the integrals of $f_i dx/2y$ from $P$ to $Q$ for each $f_i$ in $F$
by formally integrating a power series in a local parameter $t$
$P$ and $Q$ MUST be in the same residue disc for this result to make sense.
INPUT:
- F a list of functions $f_i$
- P a point on self
- Q a point on self (in the same residue disc as P)
OUTPUT:
The integrals $\int_P^Q f_i dx/2y$
EXAMPLES::
sage: K = pAdicField(17, 5)
sage: E = EllipticCurve(K, [-31/3, -2501/108]) # 11a
sage: P = E(K(14/3), K(11/2))
sage: TP = E.teichmuller(P);
sage: x,y = E.monsky_washnitzer_gens()
sage: E.tiny_integrals([1,x],P, TP) == E.tiny_integrals_on_basis(P,TP)
True
::
sage: K = pAdicField(11, 5)
sage: x = polygen(K)
sage: C = HyperellipticCurve(x^5 + 33/16*x^4 + 3/4*x^3 + 3/8*x^2 - 1/4*x + 1/16)
sage: P = C.lift_x(11^(-2))
sage: Q = C.lift_x(3*11^(-2))
sage: C.tiny_integrals([1],P,Q)
(3*11^3 + 7*11^4 + 4*11^5 + 7*11^6 + 5*11^7 + O(11^8))
Note that this fails if the points are not in the same residue disc::
sage: S = C(0,1/4)
sage: C.tiny_integrals([1,x,x^2,x^3],P,S)
Traceback (most recent call last):
...
ValueError: (11^-2 + O(11^3) : 11^-5 + 8*11^-2 + O(11^0) : 1 + O(11^5)) and (0 : 3 + 8*11 + 2*11^2 + 8*11^3 + 2*11^4 + O(11^5) : 1 + O(11^5)) are not in the same residue disc
"""
x, y, z = self.local_analytic_interpolation(P, Q) #homogeneous coordinates
x = x/z
y = y/z
dt = x.derivative() / (2*y)
integrals = []
g = self.genus()
for f in F:
try:
f_dt = f(x,y)*dt
except TypeError: #if f is a constant, not callable
f_dt = f*dt
if x.valuation() != -2:
I = sum([f_dt[n]/(n+1) for n in xrange(f_dt.degree()+1)]) # \int_0^1 f dt
else:
If_dt = f_dt.integral()
I = If_dt(Q[0]**g/Q[1]) - If_dt(P[0]**g/P[1])
integrals.append(I)
return vector(integrals)
def tiny_integrals_on_basis(self, P, Q):
r"""
Evaluate the integrals $\{\int_P^Q x^i dx/2y \}_{i=0}^{2g-1}$
by formally integrating a power series in a local parameter $t$.
$P$ and $Q$ MUST be in the same residue disc for this result to make sense.
INPUT:
- P a point on self
- Q a point on self (in the same residue disc as P)
OUTPUT:
The integrals $\{\int_P^Q x^i dx/2y \}_{i=0}^{2g-1}$
EXAMPLES::
sage: K = pAdicField(17, 5)
sage: E = EllipticCurve(K, [-31/3, -2501/108]) # 11a
sage: P = E(K(14/3), K(11/2))
sage: TP = E.teichmuller(P);
sage: E.tiny_integrals_on_basis(P, TP)
(17 + 14*17^2 + 17^3 + 8*17^4 + O(17^5), 16*17 + 5*17^2 + 8*17^3 + 14*17^4 + O(17^5))
::
sage: K = pAdicField(11, 5)
sage: x = polygen(K)
sage: C = HyperellipticCurve(x^5 + 33/16*x^4 + 3/4*x^3 + 3/8*x^2 - 1/4*x + 1/16)
sage: P = C.lift_x(11^(-2))
sage: Q = C.lift_x(3*11^(-2))
sage: C.tiny_integrals_on_basis(P,Q)
(3*11^3 + 7*11^4 + 4*11^5 + 7*11^6 + 5*11^7 + O(11^8), 3*11 + 10*11^2 + 8*11^3 + 9*11^4 + 7*11^5 + O(11^6), 4*11^-1 + 2 + 6*11 + 6*11^2 + 7*11^3 + O(11^4), 11^-3 + 6*11^-2 + 2*11^-1 + 2 + O(11^2))
Note that this fails if the points are not in the same residue disc::
sage: S = C(0,1/4)
sage: C.tiny_integrals_on_basis(P,S)
Traceback (most recent call last):
...
ValueError: (11^-2 + O(11^3) : 11^-5 + 8*11^-2 + O(11^0) : 1 + O(11^5)) and (0 : 3 + 8*11 + 2*11^2 + 8*11^3 + 2*11^4 + O(11^5) : 1 + O(11^5)) are not in the same residue disc
"""
if P == Q:
V = VectorSpace(self.base_ring(), 2*self.genus())
return V(0)
R = PolynomialRing(self.base_ring(), ['x', 'y'])
x, y = R.gens()
return self.tiny_integrals([x**i for i in range(2*self.genus())], P, Q)
def teichmuller(self, P):
r"""
Find a Teichm\:uller point in the same residue class of $P$.
Because this lift of frobenius acts as $x \mapsto x^p$,
take the Teichmuller lift of $x$ and then find a matching $y$
from that.
EXAMPLES::
sage: K = pAdicField(7, 5)
sage: E = EllipticCurve(K, [-31/3, -2501/108]) # 11a
sage: P = E(K(14/3), K(11/2))
sage: E.frobenius(P) == P
False
sage: TP = E.teichmuller(P); TP
(0 : 2 + 3*7 + 3*7^2 + 3*7^4 + O(7^5) : 1 + O(7^5))
sage: E.frobenius(TP) == TP
True
sage: (TP[0] - P[0]).valuation() > 0, (TP[1] - P[1]).valuation() > 0
(True, True)
"""
K = P[0].parent()
x = K.teichmuller(P[0])
pts = self.lift_x(x, all=True)
p = K.prime()
if (pts[0][1] - P[1]).valuation() > 0:
return pts[0]
else:
return pts[1]
def coleman_integrals_on_basis(self, P, Q, algorithm=None):
r"""
Computes the Coleman integrals $\{\int_P^Q x^i dx/2y \}_{i=0}^{2g-1}$
INPUT:
- P point on self
- Q point on self
- algorithm (optional) = None (uses Frobenius) or teichmuller (uses Teichmuller points)
OUTPUT:
the Coleman integrals $\{\int_P^Q x^i dx/2y \}_{i=0}^{2g-1}$
EXAMPLES::
sage: K = pAdicField(11, 5)
sage: x = polygen(K)
sage: C = HyperellipticCurve(x^5 + 33/16*x^4 + 3/4*x^3 + 3/8*x^2 - 1/4*x + 1/16)
sage: P = C.lift_x(2)
sage: Q = C.lift_x(3)
sage: C.coleman_integrals_on_basis(P, Q)
(10*11 + 6*11^3 + 2*11^4 + O(11^5), 11 + 9*11^2 + 7*11^3 + 9*11^4 + O(11^5), 3 + 10*11 + 5*11^2 + 9*11^3 + 4*11^4 + O(11^5), 3 + 11 + 5*11^2 + 4*11^4 + O(11^5))
sage: C.coleman_integrals_on_basis(P, Q, algorithm='teichmuller')
(10*11 + 6*11^3 + 2*11^4 + O(11^5), 11 + 9*11^2 + 7*11^3 + 9*11^4 + O(11^5), 3 + 10*11 + 5*11^2 + 9*11^3 + 4*11^4 + O(11^5), 3 + 11 + 5*11^2 + 4*11^4 + O(11^5))
::
sage: K = pAdicField(11,5)
sage: x = polygen(K)
sage: C = HyperellipticCurve(x^5 + 33/16*x^4 + 3/4*x^3 + 3/8*x^2 - 1/4*x + 1/16)
sage: P = C.lift_x(11^(-2))
sage: Q = C.lift_x(3*11^(-2))
sage: C.coleman_integrals_on_basis(P, Q)
(3*11^3 + 7*11^4 + 4*11^5 + 7*11^6 + 5*11^7 + O(11^8), 3*11 + 10*11^2 + 8*11^3 + 9*11^4 + 7*11^5 + O(11^6), 4*11^-1 + 2 + 6*11 + 6*11^2 + 7*11^3 + O(11^4), 11^-3 + 6*11^-2 + 2*11^-1 + 2 + O(11^2))
::
sage: R = C(0,1/4)
sage: a = C.coleman_integrals_on_basis(P,R) # long time (7s on sage.math, 2011)
sage: b = C.coleman_integrals_on_basis(R,Q) # long time (9s on sage.math, 2011)
sage: c = C.coleman_integrals_on_basis(P,Q) # long time
sage: a+b == c # long time
True
::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,8)
sage: HK = H.change_ring(K)
sage: S = HK(1,0)
sage: P = HK(0,3)
sage: T = HK(0,1,0)
sage: Q = HK.lift_x(5^-2)
sage: R = HK.lift_x(4*5^-2)
sage: HK.coleman_integrals_on_basis(S,P)
(2*5^2 + 5^4 + 5^5 + 3*5^6 + 3*5^7 + 2*5^8 + O(5^9), 5 + 2*5^2 + 4*5^3 + 2*5^4 + 3*5^6 + 4*5^7 + 2*5^8 + O(5^9))
sage: HK.coleman_integrals_on_basis(T,P)
(2*5^2 + 5^4 + 5^5 + 3*5^6 + 3*5^7 + 2*5^8 + O(5^9), 5 + 2*5^2 + 4*5^3 + 2*5^4 + 3*5^6 + 4*5^7 + 2*5^8 + O(5^9))
sage: HK.coleman_integrals_on_basis(P,S) == -HK.coleman_integrals_on_basis(S,P)
True
sage: HK.coleman_integrals_on_basis(S,Q)
(4*5 + 4*5^2 + 4*5^3 + O(5^4), 5^-1 + O(5^3))
sage: HK.coleman_integrals_on_basis(Q,R)
(4*5 + 2*5^2 + 2*5^3 + 2*5^4 + 5^5 + 5^6 + 5^7 + 3*5^8 + O(5^9), 2*5^-1 + 4 + 4*5 + 4*5^2 + 4*5^3 + 2*5^4 + 3*5^5 + 2*5^6 + O(5^7))
sage: HK.coleman_integrals_on_basis(S,R) == HK.coleman_integrals_on_basis(S,Q) + HK.coleman_integrals_on_basis(Q,R)
True
sage: HK.coleman_integrals_on_basis(T,T)
(0, 0)
sage: HK.coleman_integrals_on_basis(S,T)
(0, 0)
AUTHORS:
- Robert Bradshaw (2007-03): non-Weierstrass points
- Jennifer Balakrishnan and Robert Bradshaw (2010-02): Weierstrass points
"""
import sage.schemes.elliptic_curves.monsky_washnitzer as monsky_washnitzer
from sage.misc.profiler import Profiler
prof = Profiler()
prof("setup")
K = self.base_ring()
p = K.prime()
prec = K.precision_cap()
g = self.genus()
dim = 2*g
V = VectorSpace(K, dim)
#if P or Q is Weierstrass, use the Frobenius algorithm
if self.is_weierstrass(P):
if self.is_weierstrass(Q):
return V(0)
else:
PP = None
QQ = Q
TP = None
TQ = self.frobenius(Q)
elif self.is_weierstrass(Q):
PP = P
QQ = None
TQ = None
TP = self.frobenius(P)
elif self.is_same_disc(P,Q):
return self.tiny_integrals_on_basis(P,Q)
elif algorithm == 'teichmuller':
prof("teichmuller")
PP = TP = self.teichmuller(P)
QQ = TQ = self.teichmuller(Q)
evalP, evalQ = TP, TQ
else:
prof("frobPQ")
TP = self.frobenius(P)
TQ = self.frobenius(Q)
PP, QQ = P, Q
prof("tiny integrals")
if TP == None:
P_to_TP = V(0)
else:
if TP!=None:
TPv = (TP[0]**g/TP[1]).valuation()
xTPv = TP[0].valuation()
else:
xTPv = TPv = +Infinity
if TQ!=None:
TQv = (TQ[0]**g/TQ[1]).valuation()
xTQv = TQ[0].valuation()
else:
xTQv = TQv = +Infinity
offset = (2*g-1)*max(TPv, TQv)
if offset == +Infinity:
offset = (2*g-1)*min(TPv,TQv)
if (offset > prec and (xTPv <0 or xTQv <0) and (self.residue_disc(P) == self.change_ring(GF(p))(0,1,0) or self.residue_disc(Q) == self.change_ring(GF(p))(0,1,0))):
newprec = offset + prec
K = pAdicField(p,newprec)
A = PolynomialRing(RationalField(),'x')
f = A(self.hyperelliptic_polynomials()[0])
from sage.schemes.hyperelliptic_curves.constructor import HyperellipticCurve
self = HyperellipticCurve(f).change_ring(K)
xP = P[0]
xPv = xP.valuation()
xPnew = K(sum(xP.list()[i]*p**(xPv + i) for i in range(len(xP.list()))))
PP = P = self.lift_x(xPnew)
TP = self.frobenius(P)
xQ = Q[0]
xQv = xQ.valuation()
xQnew = K(sum(xQ.list()[i]*p**(xQv + i) for i in range(len(xQ.list()))))
QQ = Q = self.lift_x(xQnew)
TQ = self.frobenius(Q)
V = VectorSpace(K,dim)
P_to_TP = V(self.tiny_integrals_on_basis(P, TP))
if TQ == None:
TQ_to_Q = V(0)
else:
TQ_to_Q = V(self.tiny_integrals_on_basis(TQ, Q))
prof("mw calc")
try:
M_frob, forms = self._frob_calc
except AttributeError:
M_frob, forms = self._frob_calc = monsky_washnitzer.matrix_of_frobenius_hyperelliptic(self)
prof("eval f")
R = forms[0].base_ring()
try:
prof("eval f %s"%R)
if PP is None:
L = [-f(R(QQ[0]), R(QQ[1])) for f in forms] ##changed
elif QQ is None:
L = [f(R(PP[0]), R(PP[1])) for f in forms]
else:
L = [f(R(PP[0]), R(PP[1])) - f(R(QQ[0]), R(QQ[1])) for f in forms]
except ValueError:
prof("changing rings")
forms = [f.change_ring(self.base_ring()) for f in forms]
prof("eval f %s"%self.base_ring())
if PP is None:
L = [-f(QQ[0], QQ[1]) for f in forms] ##changed
elif QQ is None:
L = [f(PP[0], PP[1]) for f in forms]
else:
L = [f(PP[0], PP[1]) - f(QQ[0], QQ[1]) for f in forms]
b = V(L)
if PP is None:
b -= TQ_to_Q
elif QQ is None:
b -= P_to_TP
elif algorithm != 'teichmuller':
b -= P_to_TP + TQ_to_Q
prof("lin alg")
M_sys = matrix(K, M_frob).transpose() - 1
TP_to_TQ = M_sys**(-1) * b
prof("done")
# print prof
if algorithm == 'teichmuller':
return P_to_TP + TP_to_TQ + TQ_to_Q
else:
return TP_to_TQ
coleman_integrals_on_basis_hyperelliptic = coleman_integrals_on_basis
# def invariant_differential(self):
# """
# Returns the invariant differential $dx/2y$ on self
#
# EXAMPLES::
#
# sage: R.<x> = QQ['x']
# sage: H = HyperellipticCurve(x^3+1)
# sage: K = Qp(5,8)
# sage: HK = H.change_ring(K)
# sage: w = HK.invariant_differential(); w
# (((1+O(5^8)))*1) dx/2y
#
# ::
#
# sage: K = pAdicField(11, 6)
# sage: x = polygen(K)
# sage: C = HyperellipticCurve(x^5 + 33/16*x^4 + 3/4*x^3 + 3/8*x^2 - 1/4*x + 1/16)
# sage: C.invariant_differential()
# (((1+O(11^6)))*1) dx/2y
#
# """
# import sage.schemes.elliptic_curves.monsky_washnitzer as monsky_washnitzer
# S = monsky_washnitzer.SpecialHyperellipticQuotientRing(self)
# MW = monsky_washnitzer.MonskyWashnitzerDifferentialRing(S)
# return MW.invariant_differential()
def coleman_integral(self, w, P, Q, algorithm = 'None'):
r"""
Returns the Coleman integral $\int_P^Q w$
INPUT:
- w differential (if one of P,Q is Weierstrass, w must be odd)
- P point on self
- Q point on self
- algorithm (optional) = None (uses Frobenius) or teichmuller (uses Teichmuller points)
OUTPUT:
the Coleman integral $\int_P^Q w$
EXAMPLES::
Example of Leprevost from Kiran Kedlaya
The first two should be zero as $(P-Q) = 30(P-Q)$ in the Jacobian
and $dx/2y$ and $x dx/2y$ are holomorphic.
sage: K = pAdicField(11, 6)
sage: x = polygen(K)
sage: C = HyperellipticCurve(x^5 + 33/16*x^4 + 3/4*x^3 + 3/8*x^2 - 1/4*x + 1/16)
sage: P = C(-1, 1); P1 = C(-1, -1)
sage: Q = C(0, 1/4); Q1 = C(0, -1/4)
sage: x, y = C.monsky_washnitzer_gens()
sage: w = C.invariant_differential()
sage: w.coleman_integral(P, Q)
O(11^6)
sage: C.coleman_integral(x*w, P, Q)
O(11^6)
sage: C.coleman_integral(x^2*w, P, Q)
7*11 + 6*11^2 + 3*11^3 + 11^4 + 5*11^5 + O(11^6)
::
sage: p = 71; m = 4
sage: K = pAdicField(p, m)
sage: x = polygen(K)
sage: C = HyperellipticCurve(x^5 + 33/16*x^4 + 3/4*x^3 + 3/8*x^2 - 1/4*x + 1/16)
sage: P = C(-1, 1); P1 = C(-1, -1)
sage: Q = C(0, 1/4); Q1 = C(0, -1/4)
sage: x, y = C.monsky_washnitzer_gens()
sage: w = C.invariant_differential()
sage: w.integrate(P, Q), (x*w).integrate(P, Q)
(O(71^4), O(71^4))
sage: R, R1 = C.lift_x(4, all=True)
sage: w.integrate(P, R)
21*71 + 67*71^2 + 27*71^3 + O(71^4)
sage: w.integrate(P, R) + w.integrate(P1, R1)
O(71^4)
A simple example, integrating dx::
sage: R.<x> = QQ['x']
sage: E= HyperellipticCurve(x^3-4*x+4)
sage: K = Qp(5,10)
sage: EK = E.change_ring(K)
sage: P = EK(2, 2)
sage: Q = EK.teichmuller(P)
sage: x, y = EK.monsky_washnitzer_gens()
sage: EK.coleman_integral(x.diff(), P, Q)
5 + 2*5^2 + 5^3 + 3*5^4 + 4*5^5 + 2*5^6 + 3*5^7 + 3*5^9 + O(5^10)
sage: Q[0] - P[0]
5 + 2*5^2 + 5^3 + 3*5^4 + 4*5^5 + 2*5^6 + 3*5^7 + 3*5^9 + O(5^10)
Yet another example::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x*(x-1)*(x+9))
sage: K = Qp(7,10)
sage: HK = H.change_ring(K)
sage: import sage.schemes.elliptic_curves.monsky_washnitzer as mw
sage: M_frob, forms = mw.matrix_of_frobenius_hyperelliptic(HK)
sage: w = HK.invariant_differential()
sage: x,y = HK.monsky_washnitzer_gens()
sage: f = forms[0]
sage: S = HK(9,36)
sage: Q = HK.teichmuller(S)
sage: P = HK(-1,4)
sage: b = x*w*w._coeff.parent()(f)
sage: HK.coleman_integral(b,P,Q)
7 + 7^2 + 4*7^3 + 5*7^4 + 3*7^5 + 7^6 + 5*7^7 + 3*7^8 + 4*7^9 + 4*7^10 + O(7^11)
::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3+1)
sage: K = Qp(5,8)
sage: HK = H.change_ring(K)
sage: w = HK.invariant_differential()
sage: P = HK(0,1)
sage: Q = HK.lift_x(5)
sage: x,y = HK.monsky_washnitzer_gens()
sage: (2*y*w).coleman_integral(P,Q)
5 + O(5^9)
sage: xloc,yloc,zloc = HK.local_analytic_interpolation(P,Q)
sage: I2 = (xloc.derivative()/(2*yloc)).integral()
sage: I2(1)-I2(0)
3*5 + 2*5^2 + 2*5^3 + 5^4 + 4*5^6 + 5^7 + O(5^9)
sage: HK.coleman_integral(w,P,Q)
3*5 + 2*5^2 + 2*5^3 + 5^4 + 4*5^6 + 5^7 + O(5^9)
Integrals involving Weierstrass points::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,8)
sage: HK = H.change_ring(K)
sage: S = HK(1,0)
sage: P = HK(0,3)
sage: negP = HK(0,-3)
sage: T = HK(0,1,0)
sage: w = HK.invariant_differential()
sage: x,y = HK.monsky_washnitzer_gens()
sage: HK.coleman_integral(w*x^3,S,T)
0
sage: HK.coleman_integral(w*x^3,T,S)
0
sage: HK.coleman_integral(w,S,P)
2*5^2 + 5^4 + 5^5 + 3*5^6 + 3*5^7 + 2*5^8 + O(5^9)
sage: HK.coleman_integral(w,T,P)
2*5^2 + 5^4 + 5^5 + 3*5^6 + 3*5^7 + 2*5^8 + O(5^9)
sage: HK.coleman_integral(w*x^3,T,P)
5^2 + 2*5^3 + 3*5^6 + 3*5^7 + O(5^8)
sage: HK.coleman_integral(w*x^3,S,P)
5^2 + 2*5^3 + 3*5^6 + 3*5^7 + O(5^8)
sage: HK.coleman_integral(w, P, negP, algorithm='teichmuller')
5^2 + 4*5^3 + 2*5^4 + 2*5^5 + 3*5^6 + 2*5^7 + 4*5^8 + O(5^9)
sage: HK.coleman_integral(w, P, negP)
5^2 + 4*5^3 + 2*5^4 + 2*5^5 + 3*5^6 + 2*5^7 + 4*5^8 + O(5^9)
AUTHORS:
- Robert Bradshaw (2007-03)
- Kiran Kedlaya (2008-05)
- Jennifer Balakrishnan (2010-02)
"""
# TODO: implement Jacobians and show the relationship directly
import sage.schemes.elliptic_curves.monsky_washnitzer as monsky_washnitzer
K = self.base_ring()
prec = K.precision_cap()
S = monsky_washnitzer.SpecialHyperellipticQuotientRing(self, K)
MW = monsky_washnitzer.MonskyWashnitzerDifferentialRing(S)
w = MW(w)
f, vec = w.reduce_fast()
basis_values = self.coleman_integrals_on_basis(P, Q, algorithm)
dim = len(basis_values)
x,y = self.local_coordinates_at_infinity(2*prec)
if self.is_weierstrass(P):
if self.is_weierstrass(Q):
return 0
elif f == 0:
return sum([vec[i] * basis_values[i] for i in range(dim)])
elif w._coeff(x,-y)*x.derivative()/(-2*y)+w._coeff(x,y)*x.derivative()/(2*y) == 0:
return self.coleman_integral(w,self(Q[0],-Q[1]), self(Q[0],Q[1]), algorithm)/2
else:
raise ValueError, "The differential is not odd: use coleman_integral_from_weierstrass_via_boundary"
elif self.is_weierstrass(Q):
if f == 0:
return sum([vec[i] * basis_values[i] for i in range(dim)])
elif w._coeff(x,-y)*x.derivative()/(-2*y)+w._coeff(x,y)*x.derivative()/(2*y) == 0:
return -self.coleman_integral(w,self(P[0],-P[1]), self(P[0],P[1]), algorithm)/2
else:
raise ValueError, "The differential is not odd: use coleman_integral_from_weierstrass_via_boundary"
else:
return f(Q[0], Q[1]) - f(P[0], P[1]) + sum([vec[i] * basis_values[i] for i in range(dim)]) # this is just a dot product...
def frobenius(self, P=None):
"""
Returns the $p$-th power lift of Frobenius of $P$
EXAMPLES::
sage: K = Qp(11, 5)
sage: R.<x> = K[]
sage: E = HyperellipticCurve(x^5 - 21*x - 20)
sage: P = E.lift_x(2)
sage: E.frobenius(P)
(2 + 10*11 + 5*11^2 + 11^3 + O(11^5) : 5 + 9*11 + 2*11^2 + 2*11^3 + O(11^5) : 1 + O(11^5))
sage: Q = E.teichmuller(P); Q
(2 + 10*11 + 4*11^2 + 9*11^3 + 11^4 + O(11^5) : 5 + 9*11 + 6*11^2 + 11^3 + 6*11^4 + O(11^5) : 1 + O(11^5))
sage: E.frobenius(Q)
(2 + 10*11 + 4*11^2 + 9*11^3 + 11^4 + O(11^5) : 5 + 9*11 + 6*11^2 + 11^3 + 6*11^4 + O(11^5) : 1 + O(11^5))
::
sage: R.<x> = QQ[]
sage: H = HyperellipticCurve(x^5-23*x^3+18*x^2+40*x)
sage: Q = H(0,0)
sage: u,v = H.local_coord(Q,prec=100)
sage: K = Qp(11,5)
sage: L.<a> = K.extension(x^20-11)
sage: HL = H.change_ring(L)
sage: S = HL(u(a),v(a))
sage: HL.frobenius(S)
(8*a^22 + 10*a^42 + 4*a^44 + 2*a^46 + 9*a^48 + 8*a^50 + a^52 + 7*a^54 +
7*a^56 + 5*a^58 + 9*a^62 + 5*a^64 + a^66 + 6*a^68 + a^70 + 6*a^74 +
2*a^76 + 2*a^78 + 4*a^82 + 5*a^84 + 2*a^86 + 7*a^88 + a^90 + 6*a^92 +
a^96 + 5*a^98 + 2*a^102 + 2*a^106 + 6*a^108 + 8*a^110 + 3*a^112 +
a^114 + 8*a^116 + 10*a^118 + 3*a^120 + O(a^122) :
a^11 + 7*a^33 + 7*a^35 + 4*a^37 + 6*a^39 + 9*a^41 + 8*a^43 + 8*a^45 +
a^47 + 7*a^51 + 4*a^53 + 5*a^55 + a^57 + 7*a^59 + 5*a^61 + 9*a^63 +
4*a^65 + 10*a^69 + 3*a^71 + 2*a^73 + 9*a^75 + 10*a^77 + 6*a^79 +
10*a^81 + 7*a^85 + a^87 + 4*a^89 + 8*a^91 + a^93 + 8*a^95 + 2*a^97 +
7*a^99 + a^101 + 3*a^103 + 6*a^105 + 7*a^107 + 4*a^109 + O(a^111) :
1 + O(a^100))
AUTHORS:
- Robert Bradshaw and Jennifer Balakrishnan (2010-02)
"""
try:
_frob = self._frob
except AttributeError:
K = self.base_ring()
p = K.prime()
x = K['x'].gen(0)
f, f2 = self.hyperelliptic_polynomials()
if f2 != 0:
raise NotImplementedError, "Curve must be in weierstrass normal form."
h = (f(x**p) - f**p)
def _frob(P):
if P == self(0,1,0):
return P
x0 = P[0]
y0 = P[1]
try:
uN = (1 + h(x0)/y0**(2*p)).sqrt()
yres=y0**p * uN
xres=x0**p
if (yres-y0).valuation() == 0:
yres=-yres
return self.point([xres,yres, K(1)])
except (TypeError, NotImplementedError):
uN2 = 1 + h(x0)/y0**(2*p)
#yfrob2 = f(x)
c = uN2.list()[0]
v = uN2.valuation()
a = uN2.parent().gen()
uN = self.newton_sqrt(uN2,c.sqrt()*a**(v//2),K.precision_cap())
yres = y0**p *uN
xres = x0**p
if (yres - y0).valuation() == 0:
yres = -yres
try:
return self(xres,yres)
except ValueError:
return self._curve_over_ram_extn(xres,yres)
self._frob = _frob
if P is None:
return _frob
else:
return _frob(P)
def newton_sqrt(self,f,x0, prec):
r"""
Takes the square root of the power series $f$ by Newton's method
NOTE:
this function should eventually be moved to $p$-adic power series ring
INPUT:
- f power series wtih coefficients in $\Q_p$ or an extension
- x0 seeds the Newton iteration
- prec precision
OUTPUT:
the square root of $f$
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^5-23*x^3+18*x^2+40*x)
sage: Q = H(0,0)
sage: u,v = H.local_coord(Q,prec=100)
sage: K = Qp(11,5)
sage: HK = H.change_ring(K)
sage: L.<a> = K.extension(x^20-11)
sage: HL = H.change_ring(L)
sage: S = HL(u(a),v(a))
sage: f = H.hyperelliptic_polynomials()[0]
sage: y = HK.newton_sqrt( f(u(a)^11), a^11,5)
sage: y^2 - f(u(a)^11)
O(a^122)
AUTHOR:
- Jennifer Balakrishnan
"""
z = x0
try:
x = f.parent().variable_name()
if x!='a' : #this is to distinguish between extensions of Qp that are finite vs. not
S = f.base_ring()[[x]]
x = S.gen()
except ValueError:
pass
z = x0
loop_prec = (log(RR(prec))/log(RR(2))).ceil()
for i in range(loop_prec):
z = (z+f/z)/2
try:
return z + O(x**prec)
except (NameError,ArithmeticError,TypeError):
return z
def curve_over_ram_extn(self,deg):
r"""
Returns self over $\Q_p(p^(1/deg))$
INPUT:
- deg: the degree of the ramified extension
OUTPUT:
self over $\Q_p(p^(1/deg))$
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^5-23*x^3+18*x^2+40*x)
sage: K = Qp(11,5)
sage: HK = H.change_ring(K)
sage: HL = HK.curve_over_ram_extn(2)
sage: HL
Hyperelliptic Curve over Eisenstein Extension of 11-adic Field with capped relative precision 5 in a defined by (1 + O(11^5))*x^2 + (O(11^6))*x + (10*11 + 10*11^2 + 10*11^3 + 10*11^4 + 10*11^5 + O(11^6)) defined by (1 + O(a^10))*y^2 = (1 + O(a^10))*x^5 + (10 + 8*a^2 + 10*a^4 + 10*a^6 + 10*a^8 + O(a^10))*x^3 + (7 + a^2 + O(a^10))*x^2 + (7 + 3*a^2 + O(a^10))*x
AUTHOR:
- Jennifer Balakrishnan
"""
from sage.schemes.hyperelliptic_curves.constructor import HyperellipticCurve
K = self.base_ring()
p = K.prime()
A = PolynomialRing(QQ,'x')
x = A.gen()
J = K.extension(x**deg-p,names='a')
pol = self.hyperelliptic_polynomials()[0]
H = HyperellipticCurve(A(pol))
HJ = H.change_ring(J)
self._curve_over_ram_extn = HJ
self._curve_over_ram_extn._curve_over_Qp = self
return HJ
def get_boundary_point(self, curve_over_extn, P):
"""
Given self over an extension field, find a point in the disc of $P$ near the boundary
INPUT:
- curve_over_extn: self over a totally ramified extension
- P: Weierstrass point
OUTPUT:
a point in the disc of $P$ near the boundary
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(3,6)
sage: HK = H.change_ring(K)
sage: P = HK(1,0)
sage: J.<a> = K.extension(x^30-3)
sage: HJ = H.change_ring(J)
sage: S = HK.get_boundary_point(HJ,P)
sage: S
(1 + 2*a^2 + 2*a^6 + 2*a^18 + a^32 + a^34 + a^36 + 2*a^38 + 2*a^40 + a^42 + 2*a^44 + a^48 + 2*a^50 + 2*a^52 + a^54 + a^56 + 2*a^60 + 2*a^62 + a^70 + 2*a^72 + a^76 + 2*a^78 + a^82 + a^88 + a^96 + 2*a^98 + 2*a^102 + a^104 + 2*a^106 + a^108 + 2*a^110 + a^112 + 2*a^116 + a^126 + 2*a^130 + 2*a^132 + a^144 + 2*a^148 + 2*a^150 + a^152 + 2*a^154 + a^162 + a^164 + a^166 + a^168 + a^170 + a^176 + a^178 + O(a^180) : a + O(a^181) : 1 + O(a^180))
AUTHOR:
- Jennifer Balakrishnan
"""
J = curve_over_extn.base_ring()
a = J.gen()
prec2 = J.precision_cap()
x,y = self.local_coord(P,prec2)
return curve_over_extn(x(a),y(a))
def P_to_S(self, P, S):
r"""
Given a finite Weierstrass point $P$ and a point $S$
in the same disc, computes the Coleman integrals $\{\int_P^S x^i dx/2y \}_{i=0}^{2g-1}$
INPUT:
- P: finite Weierstrass point
- S: point in disc of P
OUTPUT:
Coleman integrals $\{\int_P^S x^i dx/2y \}_{i=0}^{2g-1}$
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,4)
sage: HK = H.change_ring(K)
sage: P = HK(1,0)
sage: HJ = HK.curve_over_ram_extn(10)
sage: S = HK.get_boundary_point(HJ,P)
sage: HK.P_to_S(P, S)
(2*a + 4*a^3 + 2*a^11 + 4*a^13 + 2*a^17 + 2*a^19 + a^21 + 4*a^23 + a^25 + 2*a^27 + 2*a^29 + 3*a^31 + 4*a^33 + O(a^35), a^-5 + 2*a + 2*a^3 + a^7 + 3*a^11 + a^13 + 3*a^15 + 3*a^17 + 2*a^19 + 4*a^21 + 4*a^23 + 4*a^25 + 2*a^27 + a^29 + a^31 + 3*a^33 + O(a^35))
AUTHOR:
- Jennifer Balakrishnan
"""
prec = self.base_ring().precision_cap()
deg = (S[0]).parent().defining_polynomial().degree()
prec2= prec*deg
x,y = self.local_coord(P,prec2)
g = self.genus()
integrals = [((x**k*x.derivative()/(2*y)).integral()) for k in range(2*g)]
val = [I(S[1]) for I in integrals]
return vector(val)
def coleman_integral_P_to_S(self,w,P,S):
r"""
Given a finite Weierstrass point $P$ and a point $S$
in the same disc, computes the Coleman integral $\int_P^S w$
INPUT:
- w: differential
- P: Weierstrass point
- S: point in the same disc of P (S is defined over an extension of $\Q_p$; coordinates
of S are given in terms of uniformizer $a$)
OUTPUT:
Coleman integral $\int_P^S w$ in terms of $a$
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,4)
sage: HK = H.change_ring(K)
sage: P = HK(1,0)
sage: J.<a> = K.extension(x^10-5)
sage: HJ = H.change_ring(J)
sage: S = HK.get_boundary_point(HJ,P)
sage: x,y = HK.monsky_washnitzer_gens()
sage: S[0]-P[0] == HK.coleman_integral_P_to_S(x.diff(),P,S)
True
sage: HK.coleman_integral_P_to_S(HK.invariant_differential(),P,S) == HK.P_to_S(P,S)[0]
True
AUTHOR:
- Jennifer Balakrishnan
"""
prec = self.base_ring().precision_cap()
deg = S[0].parent().defining_polynomial().degree()
prec2= prec*deg
x,y = self.local_coord(P,prec2)
g = self.genus()
int_sing = (w.coeff()(x,y)*x.derivative()/(2*y)).integral()
int_sing_a = int_sing(S[1])
return int_sing_a
def S_to_Q(self,S,Q):
r"""
Given $S$ a point on self over an extension field, computes the
Coleman integrals $\{\int_S^Q x^i dx/2y \}_{i=0}^{2g-1}$
**one should be able to feed $S,Q$ into coleman_integral,
but currently that segfaults**
INPUT:
- S: a point with coordinates in an extension of $\Q_p$ (with unif. a)
- Q: a non-Weierstrass point defined over $\Q_p$
OUTPUT:
the Coleman integrals $\{\int_S^Q x^i dx/2y \}_{i=0}^{2g-1}$ in terms of $a$
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,6)
sage: HK = H.change_ring(K)
sage: J.<a> = K.extension(x^20-5)
sage: HJ = H.change_ring(J)
sage: w = HK.invariant_differential()
sage: x,y = HK.monsky_washnitzer_gens()
sage: P = HK(1,0)
sage: Q = HK(0,3)
sage: S = HK.get_boundary_point(HJ,P)
sage: P_to_S = HK.P_to_S(P,S)
sage: S_to_Q = HJ.S_to_Q(S,Q)
sage: P_to_S + S_to_Q
(2*a^40 + a^80 + a^100 + O(a^105), a^20 + 2*a^40 + 4*a^60 + 2*a^80 + O(a^105))
sage: HK.coleman_integrals_on_basis(P,Q)
(2*5^2 + 5^4 + 5^5 + 3*5^6 + O(5^7), 5 + 2*5^2 + 4*5^3 + 2*5^4 + 5^6 + O(5^7))
AUTHOR:
- Jennifer Balakrishnan
"""
FS = self.frobenius(S)
FS = (FS[0],FS[1])
FQ = self.frobenius(Q)
import sage.schemes.elliptic_curves.monsky_washnitzer as monsky_washnitzer
try:
M_frob, forms = self._frob_calc
except AttributeError:
M_frob, forms = self._frob_calc = monsky_washnitzer.matrix_of_frobenius_hyperelliptic(self)
try:
HJ = self._curve_over_ram_extn
K = HJ.base_ring()
except AttributeError:
HJ = S.scheme()
K = self.base_ring()
g = self.genus()
prec2 = K.precision_cap()
p = K.prime()
dim = 2*g
V = VectorSpace(K,dim)
if S == FS:
S_to_FS = V(dim*[0])
else:
P = self(ZZ(FS[0][0]),ZZ(FS[1][0]))
x,y = self.local_coord(P,prec2)
integrals = [(x**i*x.derivative()/(2*y)).integral() for i in range(dim)]
S_to_FS = vector([I(FS[1])-I(S[1]) for I in integrals])
if HJ(Q[0],Q[1]) == HJ(FQ):
FQ_to_Q = V(dim*[0])
else:
FQ_to_Q = V(self.tiny_integrals_on_basis(FQ, Q))
try:
L = [f(K(S[0]), K(S[1])) - f(K(Q[0]), K(Q[1])) for f in forms]
except ValueError:
forms = [f.change_ring(K) for f in forms]
L = [f(S[0], S[1]) - f(Q[0], Q[1]) for f in forms]
b = V(L)
M_sys = matrix(K, M_frob).transpose() - 1
B = (~M_sys)
v = [B.list()[i].valuation() for i in range(len(B.list()))]
vv= min(v)
B = (p**(-vv)*B).change_ring(K)
B = p**(vv)*B
return B*(b-S_to_FS-FQ_to_Q)
def coleman_integral_S_to_Q(self,w,S,Q):
r"""
Computes the Coleman integral $\int_S^Q w$
**one should be able to feed $S,Q$ into coleman_integral,
but currently that segfaults**
INPUT:
- w: a differential
- S: a point with coordinates in an extension of $\Q_p$
- Q: a non-Weierstrass point defined over $\Q_p$
OUTPUT:
the Coleman integral $\int_S^Q w$
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,6)
sage: HK = H.change_ring(K)
sage: J.<a> = K.extension(x^20-5)
sage: HJ = H.change_ring(J)
sage: x,y = HK.monsky_washnitzer_gens()
sage: P = HK(1,0)
sage: Q = HK(0,3)
sage: S = HK.get_boundary_point(HJ,P)
sage: P_to_S = HK.coleman_integral_P_to_S(y.diff(),P,S)
sage: S_to_Q = HJ.coleman_integral_S_to_Q(y.diff(),S,Q)
sage: P_to_S + S_to_Q
3 + O(a^120)
sage: HK.coleman_integral(y.diff(),P,Q)
3 + O(5^6)
AUTHOR:
- Jennifer Balakrishnan
"""
import sage.schemes.elliptic_curves.monsky_washnitzer as monsky_washnitzer
K = self.base_ring()
R = monsky_washnitzer.SpecialHyperellipticQuotientRing(self, K)
MW = monsky_washnitzer.MonskyWashnitzerDifferentialRing(R)
w = MW(w)
f, vec = w.reduce_fast()
g = self.genus()
const = f(Q[0],Q[1])-f(S[0],S[1])
if vec == vector(2*g*[0]):
return const
else:
basis_values = self.S_to_Q(S, Q)
dim = len(basis_values)
dot = sum([vec[i] * basis_values[i] for i in range(dim)])
return const + dot
def coleman_integral_from_weierstrass_via_boundary(self, w, P, Q, d):
r"""
Computes the Coleman integral $\int_P^Q w$ via a boundary point
in the disc of $P$, defined over a degree $d$ extension
INPUT:
- w: a differential
- P: a Weierstrass point
- Q: a non-Weierstrass point
- d: degree of extension where coordinates of boundary point lie
OUTPUT:
the Coleman integral $\int_P^Q w$, written in terms of the uniformizer
$a$ of the degree $d$ extension
EXAMPLES::
sage: R.<x> = QQ['x']
sage: H = HyperellipticCurve(x^3-10*x+9)
sage: K = Qp(5,6)
sage: HK = H.change_ring(K)
sage: P = HK(1,0)
sage: Q = HK(0,3)
sage: x,y = HK.monsky_washnitzer_gens()
sage: HK.coleman_integral_from_weierstrass_via_boundary(y.diff(),P,Q,20)
3 + O(a^120)
sage: HK.coleman_integral(y.diff(),P,Q)
3 + O(5^6)
sage: w = HK.invariant_differential()
sage: HK.coleman_integral_from_weierstrass_via_boundary(w,P,Q,20)
2*a^40 + a^80 + a^100 + O(a^105)
sage: HK.coleman_integral(w,P,Q)
2*5^2 + 5^4 + 5^5 + 3*5^6 + O(5^7)
AUTHOR:
- Jennifer Balakrishnan
"""
HJ = self.curve_over_ram_extn(d)
S = self.get_boundary_point(HJ,P)
P_to_S = self.coleman_integral_P_to_S(w,P,S)
S_to_Q = HJ.coleman_integral_S_to_Q(w,S,Q)
return P_to_S + S_to_Q