Stability of the gapless pure point spectrum of self-adjoint operators
arXiv:2211.05670 · doi:10.1063/5.0187017
Abstract
We consider a self-adjoint operator on a separable Hilbert space, with pure-point and simple spectrum with accumulations at finite points. Explicit conditions are stated on the eigenvalues of and on the bounded perturbation ensuring the global stability of the spectral nature of .
34 pages