2 papers
math.SP2026
On spectral stability for self-adjoint extensions
Mario Alberto Ruiz Caballero
We prove that given a symmetric completely non-selfadjoint operator with finite deficiency indices on a Hilbert space and a boundary triplet $\left(\mathbb{C}^{n},Γ_{1}…
math.SP2025
On Spectral Stability for Rank One Perturbations
Mario Alberto Ruiz Caballero, Rafael del Rio
Embedded point spectra of rank one singular perturbations of an arbitrary self-adjoint operator A on a Hilbert space H is studied. It is shown that these perturbations can be regar…