On Symmetries in the Theory of Finite Rank Singular Perturbations

Seppo Hassi, Sergii Kuzhel

For a nonnegative self-adjoint operator $A_0$ acting on a Hilbert space $\mathfrak{H}$ singular perturbations of the form $A_0+V,V={\sum }_1^n{b}_{ij}<{\psi }_j,\cdot >{\psi }_i$ are studie…