2 papers
math.NT2025
Norm bounds on Eisenstein series
Dubi Kelmer, Alex Kontorovich, Christopher Lutsko
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…
math.GT2024
Kleinian sphere packings, reflection groups, and arithmeticity
Nikolay Bogachev, Alexander Kolpakov, Alex Kontorovich
In this paper we study crystallographic sphere packings and Kleinian sphere packings, introduced first by Kontorovich and Nakamura in 2017 and then studied further by Kapovich and…