English

Local average of the hyperbolic circle problem for Fuchsian groups

Number Theory 2017-09-12 v1

Abstract

Let ΓPSL(2,R)\Gamma\subseteq PSL(2,{\bf R}) be a finite volume Fuchsian group. The hyperbolic circle problem is the estimation of the number of elements of the Γ\Gamma-orbit of zz in a hyperbolic circle around ww of radius RR, where zz and ww are given points of the upper half plane and RR is a large number. An estimate with error term e23Re^{{2\over 3}R} is known, and this has not been improved for any group. Recently Risager and Petridis proved that in the special case Γ=PSL(2,Z)\Gamma =PSL(2,{\bf Z}) taking z=wz=w and averaging over zz in a certain way the error term can be improved to e(712+ϵ)Re^{\left({7\over {12}}+\epsilon\right)R}. Here we show such an improvement for a general Γ\Gamma, our error term is e(58+ϵ)Re^{\left({5\over 8}+\epsilon\right)R} (which is better that e23Re^{{2\over 3}R} but weaker than the estimate of Risager and Petridis in the case Γ=PSL(2,Z)\Gamma =PSL(2,{\bf Z})). Our main tool is our generalization of the Selberg trace formula proved earlier.

Keywords

Cite

@article{arxiv.1709.03282,
  title  = {Local average of the hyperbolic circle problem for Fuchsian groups},
  author = {András Biró},
  journal= {arXiv preprint arXiv:1709.03282},
  year   = {2017}
}

Comments

Accepted by Mathematika

R2 v1 2026-06-22T21:38:46.577Z