50 lines
2.2 KiB
Python
50 lines
2.2 KiB
Python
def de_rham_witt_lift_form0(omega):
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C = omega.curve
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omega_regular = omega.regular_form() #Present omega0 in the form P dx + Q dy
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#Now the obvious lift of omega0 = P dx + Q dy to de Rham-Witt is [P] d[x] + [Q] d[y]
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return omega_regular.dx.teichmuller()*(C.x.teichmuller().diffn()) + omega_regular.dy.teichmuller()*(C.y.teichmuller().diffn())
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def de_rham_witt_lift_form8(omega):
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C = omega.curve
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g = C.genus()
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omega_regular = second_patch(omega).regular_form()
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omega_regular = (second_patch(omega_regular.dx), second_patch(omega_regular.dy))
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u = (C.x)^(-1)
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v = (C.y)/(C.x)^(g+1)
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omega_lift = omega_regular[0].teichmuller()*(u.teichmuller().diffn()) + omega_regular[1].teichmuller()*(v.teichmuller().diffn())
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return omega_lift
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def de_rham_witt_lift(cech_class, prec = 50):
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C = cech_class.curve
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g = C.genus()
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omega0 = cech_class.omega0
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omega8 = cech_class.omega8
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fct = cech_class.f
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omega0_lift = de_rham_witt_lift_form0(omega0)
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omega8_lift = de_rham_witt_lift_form8(omega8)
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aux = omega0_lift - omega8_lift - fct.teichmuller().diffn() # now aux is of the form (V(smth) + dV(smth), V(smth))
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if aux.h1.function != 0:
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raise ValueError('Something went wrong - aux is not of the form (V(smth) + dV(smth), V(smth)).')
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decom_aux_h2 = decomposition_g0_g8(aux.h2, prec=prec) #decompose dV(smth) in aux as smth regular on U0 - smth regular on U8.
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aux_h2 = decom_aux_h2[0]
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aux_f = decom_aux_h2[2]
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aux_omega0 = decomposition_omega0_omega8(aux.omega, prec=prec)[0]
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result = superelliptic_drw_cech(omega0_lift - aux_omega0.verschiebung(), fct.teichmuller() + aux_h2.verschiebung() + aux_f.verschiebung())
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return result
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def crystalline_cohomology_basis(self, prec = 50, info = 0):
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result = []
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prec1 = prec
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for i, a in enumerate(self.de_rham_basis()):
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if info:
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print("Computing " + str(i) +". basis element")
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while True:
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try:
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result += [de_rham_witt_lift(a, prec = prec1)]
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break
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except IndexError:
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prec1 += 100
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result += [de_rham_witt_lift(a, prec = prec1)]
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return result
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superelliptic.crystalline_cohomology_basis = crystalline_cohomology_basis |