English

Rational torsion on the generalized Jacobian of a modular curve with cuspidal modulus

Number Theory 2016-06-22 v1 Algebraic Geometry

Abstract

We consider the generalized Jacobian J~0(N)\widetilde{J}_0(N) of a modular curve X0(N)X_0(N) with respect to a reduced divisor given by the sum of all cusps on it. When NN is a power of a prime 5\geq 5, we exhibit that the group of rational torsion points J~0(N)(Q)Tor\widetilde{J}_0(N)(\mathbb{Q})_{\mathrm{Tor}} tends to be much smaller than the classical Jacobian.

Keywords

Cite

@article{arxiv.1606.06362,
  title  = {Rational torsion on the generalized Jacobian of a modular curve with cuspidal modulus},
  author = {Takao Yamazaki and Yifan Yang},
  journal= {arXiv preprint arXiv:1606.06362},
  year   = {2016}
}

Comments

17 pages