English

Spectral gap of random covers of negatively curved noncompact surfaces

Spectral Theory 2025-05-13 v1

Abstract

Let (X,g)(X,g) be a complete noncompact geometrically finite surface with pinched negative curvature b2Kg1-b^2\leq K_g \leq -1. Let λ0(X~)\lambda_0(\widetilde{X}) denote the bottom of the L2L^2-spectrum of the Laplacian on the universal cover X~\widetilde{X}. We show that a uniformly random degree-nn cover XnX_n of XX has no eigenvalues below λ0(X~)ε\lambda_0(\widetilde{X})-\varepsilon other than those of XX and with the same multiplicity, with probability tending to 11 as nn\to \infty. This extends a result of Hide--Magee to metrics of pinched negative curvature.

Keywords

Cite

@article{arxiv.2505.07056,
  title  = {Spectral gap of random covers of negatively curved noncompact surfaces},
  author = {Julien Moy},
  journal= {arXiv preprint arXiv:2505.07056},
  year   = {2025}
}

Comments

22 pages