An additive problem in the Fourier coefficients of cusp forms
Abstract
We establish an estimate on sums of shifted products of Fourier coefficients coming from holomorphic or Maass cusp forms of arbitrary level and nebentypus. These sums are analogous to the binary additive divisor sum which has been studied extensively. As an application we derive, extending work of Duke, Friedlander and Iwaniec, a subconvex estimate on the critical line for L-functions associated to character twists of these cusp forms.
Keywords
Cite
@article{arxiv.math/0101096,
title = {An additive problem in the Fourier coefficients of cusp forms},
author = {Gergely Harcos},
journal= {arXiv preprint arXiv:math/0101096},
year = {2024}
}
Comments
16 pages, LaTeX2e; v2: lots of changes, Theorem 2 is new, notation changed to standard one, abstract and further references added; v3: minor changes, some restriction imposed in Theorem 2, additional references; v4: introduction revised, references added, typos corrected; v5: final, revised version incorporating suggestions by the referee (e.g. Section 5 was added)