3 papers
math.DG2025
Small eigenvalues of pseudo-Laplacians
Werner Ballmann, Sugata Mondal, Panagiotis Polymerakis
We extend the Otal-Rosas bound on the number of small eigenvalues of the Laplacian on a hyperbolic surface to the small eigenvalues of pseudo-Laplacians. In the process, we extend…
math.DG2025
On the spectral stability of finite coverings
Werner Ballmann, Sugata Mondal, Panagiotis Polymerakis
We prove the non-existence of new eigenvalues in for specific and random finite coverings of a complete and connected Riemannian manifold with Ricci curvature bounded…
math.DG2024
Spectral instability of coverings
Sugata Mondal, Werner Ballmann
We study the behaviour of eigenvalues, below the bottom of the essential spectrum, of the Laplacian under finite Riemannian coverings of complete and connected Riemannian manifolds…