English

Small eigenvalues of hyperbolic surfaces with many cusps

Spectral Theory 2024-10-10 v1 Analysis of PDEs

Abstract

We study topological lower bounds on the number of small Laplacian eigenvalues on hyperbolic surfaces. We show there exist constants a,b>0a,b>0 such that when (g+1)<anlogn(g+1)<a\frac{n}{\log n}, any hyperbolic surface of genus-gg with nn cusps has at least b2g+n2log(2g+n2)b\frac{2g+n-2}{\log\left(2g+n-2\right)} Laplacian eigenvalues below 14\frac{1}{4}. We also show that, under certain additional constraints on the lengths of short geodesics, the lower bound can be improved to b(2g+n2)b\left(2g+n-2\right) with the weaker condition (g+1)<an(g+1)<an.

Keywords

Cite

@article{arxiv.2410.06093,
  title  = {Small eigenvalues of hyperbolic surfaces with many cusps},
  author = {Will Hide and Joe Thomas},
  journal= {arXiv preprint arXiv:2410.06093},
  year   = {2024}
}
R2 v1 2026-06-28T19:13:06.113Z