English

On a generating function of Niebur-Poincar\'e series

Number Theory 2025-12-16 v1

Abstract

Let ΓPSL2(R)\Gamma\subset PSL_2(\mathbb{R}) be a Fuchsian group of the first kind which has a cusp ii\infty of width one. In this paper, we first consider a generating function formed with the Niebur--Poincar\'e series {Fm,s(τ)}m1\{F_{m,s}(\tau)\}_{m\ge 1} associated to ii\infty. We prove a relation between the continuation of this generating function to s=1s=1 with the resolvent kernel associated to the hyperbolic Laplacian and the non-holomorphic Eisenstein series associated to ii\infty, also at s=1s=1. Secondly, we show that, for any sNs\in \mathbb{N}, the generating function equals Poincar\'e type series involving polylogarithms. We also consider a generating function formed with derivatives in ss of the Niebur--Poincar\'e series and prove that the continuation of the generating function at s=1s=1 can be expressed in terms of Γ\Gamma-periodization of a point-pair invariant involving the Rogers dilogarithm and the Kronecker limit function associated to the non-holomorphic Eisenstein series.

Cite

@article{arxiv.2512.13167,
  title  = {On a generating function of Niebur-Poincar\'e series},
  author = {Kathrin Bringmann and Jay Jorgenson and Lejla Smajlović},
  journal= {arXiv preprint arXiv:2512.13167},
  year   = {2025}
}

Comments

24 pages

R2 v1 2026-07-01T08:24:58.081Z