English

Divisor problems for restricted Fourier coefficients of modular forms

Number Theory 2026-03-30 v2

Abstract

Let d(n)d(n) be the number of divisors of nn. We investigate the average value of d(af(p))rd(a_f(p))^r for rr a positive integer and af(p)a_f(p) the pp-th Fourier coefficient of a cuspidal eigenform ff having integral Fourier coefficients, where pp is a prime subject to a constraint on the angle associated with the normalized Fourier coefficient.

Keywords

Cite

@article{arxiv.2411.17210,
  title  = {Divisor problems for restricted Fourier coefficients of modular forms},
  author = {Yuk-Kam Lau and Wonwoong Lee},
  journal= {arXiv preprint arXiv:2411.17210},
  year   = {2026}
}

Comments

27 pages, accepted by Science China Mathematics

R2 v1 2026-06-28T20:12:48.905Z