English

Split-CM points and central values of Hecke L-series

Number Theory 2010-05-10 v1

Abstract

Split-CM points are points of the moduli space h_2/Sp_4(Z) corresponding to products E×EE \times E' of elliptic curves with the same complex multiplication. We prove that the number of split-CM points in a given class of h_2/Sp_4(Z) is related to the coefficients of a weight 3/2 modular form studied by Eichler. The main application of this result is a formula for the central value L(ψN,1)L(\psi_N, 1) of a certain Hecke L-series. The Hecke character ψN\psi_N is a twist of the canonical Hecke character ψ\psi for the elliptic Q-curve A studied by Gross, and formulas for L(ψ,1)L(\psi, 1) as well as generalizations were proven by Villegas and Zagier. The formulas for L(\psin,1)L(\psin, 1) are easily computable and numerical examples are given.

Keywords

Cite

@article{arxiv.1005.1240,
  title  = {Split-CM points and central values of Hecke L-series},
  author = {Kimberly Hopkins},
  journal= {arXiv preprint arXiv:1005.1240},
  year   = {2010}
}