42 citations · 102 across the 21 of their papers we have counts for
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math.DG2021
Bottom of spectra and coverings of orbifolds
Werner Ballmann, Panagiotis Polymerakis
We discuss the behaviour of the bottom of the spectrum of scalar Schrödinger operators under Riemannian coverings of orbifolds. We apply our results to geometrically finite and to…
math.DG2021
Small eigenvalues of Schrödinger operators over geometrically finite manifolds
Werner Ballmann, Panagiotis Polymerakis
We estimate the number of small eigenvalues of Schrödinger operators on Riemannian vector bundles over geometrically finite manifolds.
math.DG2021
On the essential spectrum of differential operators over geometrically finite orbifolds
Werner Ballmann, Panagiotis Polymerakis
We discuss the essential spectrum of essentially self-adjoint elliptic differential operators of first order and of Laplace type operators on Riemannian vector bundles over geometr…