English

Vorono\"{i} summation via switching cusps

Number Theory 2019-04-04 v1

Abstract

We consider the Fourier expansion of a Hecke (resp.\ Hecke--Maa\ss) cusp form of general level NN at the various cusps of Γ0(N)\bs\Hb\Gamma_{0}(N)\bs\Hb. We explain how to compute these coefficients via the local theory of pp-adic Whittaker functions and establish a classical Vorono\"i summation formula allowing an arbitrary additive twist. Our discussion has applications to bounding sums of Fourier coefficients and understanding the (generalised) Atkin--Lehner relations.

Keywords

Cite

@article{arxiv.1904.02025,
  title  = {Vorono\"{i} summation via switching cusps},
  author = {Edgar Assing and Andrew Corbett},
  journal= {arXiv preprint arXiv:1904.02025},
  year   = {2019}
}
R2 v1 2026-06-23T08:28:12.040Z