English

Explicit images for the Shimura Correspondence

Number Theory 2025-05-05 v1

Abstract

In 2014, Yang showed that for FAr,s,1,1NF \in \mathcal{A}_{r, s, 1, 1_N}, we have Shr(FV24)=Gχ12\textup{Sh}_{r}(F \mid V_{24}) = G \otimes \chi_{12} where GSr+2s1new(Γ0(6),(8r),(12r))G\in S^{new}_{r+2s - 1}(\Gamma_{0}(6), - \left( \frac{8}{r} \right), - \left( \frac{12}{r} \right)), where Shr\textup{Sh}_{r} is the rr-th Shimura lift associated to the theta-multiplier. He proved a similar result for (r,6)=3(r,6) = 3.\:His proofs rely on trace computations in integral and half-integral weights. In this paper, we provide a constructive proof of Yang's result. We obtain explicit formulas for Sr(F)\mathcal{S}_{r}(F), the rr-th Shimura lift associated to the eta-multiplier defined by Ahlgren, Andersen, and Dicks, when 1r231\leq r\leq 23 is odd and N=1N = 1. We also obtain formulas for lifts of Hecke eigenforms multiplied by theta-function eta-quotients and lifts of Rankin-Cohen brackets of Hecke eigenforms with theta-function eta-quotients.

Keywords

Cite

@article{arxiv.2505.01018,
  title  = {Explicit images for the Shimura Correspondence},
  author = {Matthew Boylan and Swati},
  journal= {arXiv preprint arXiv:2505.01018},
  year   = {2025}
}

Comments

35 pages, Comments are welcome

R2 v1 2026-06-28T23:18:50.156Z