English

Norm bounds on Eisenstein series

Number Theory 2025-04-18 v3

Abstract

We study the sup-norm and mean-square-norm problems for Eisenstein series on certain arithmetic hyperbolic orbifolds, producing sharp exponents for the modular surface and Picard 3-fold. The methods involve bounds for Epstein zeta functions, and counting restricted values of indefinite quadratic forms at integer points.

Keywords

Cite

@article{arxiv.2305.15162,
  title  = {Norm bounds on Eisenstein series},
  author = {Dubi Kelmer and Alex Kontorovich and Christopher Lutsko},
  journal= {arXiv preprint arXiv:2305.15162},
  year   = {2025}
}

Comments

13 pages. This version has been corrected to take into account the associated erratum

R2 v1 2026-06-28T10:44:37.107Z