The analysis of eigenvalues of Laplace and Schrödinger operators is an important and
classical topic in mathematical physics with many applications. This book presents a …

In this paper we are interested in generalizing Keller-type eigenvalue estimates for the non-
selfadjoint Schrödinger operator to the Dirac operator, imposing some suitable rigidity …

By developing the method of multipliers, we establish sufficient conditions on the magnetic
field and the complex, matrix-valued electric potential, which guarantee that the …

We investigate the effect of non-symmetric relatively bounded perturbations on the spectrum
of self-adjoint operators. In particular, we establish stability theorems for one or infinitely …

Abstract We discuss abstract Birman—Schwinger principles to study spectra of self-adjoint
operators subject to small non-self-adjoint perturbations in a factorised form. In particular, we …

We provide quantitative estimates on the location of eigenvalues of one-dimensional
discrete Dirac operators with complex ℓ^ p ℓ p-potentials for 1 ≤ p ≤ ∞ 1≤ p≤∞. As a …

We introduce concepts of essential numerical range for the linear operator pencil. In contrast
to the operator essential numerical range, the pencil essential numerical ranges are, in …

We prove that the eigenvalues of the n-dimensional massive Dirac operator D _0+ VD 0+ V,
n ≥ 2 n≥ 2, perturbed by a potential V, possibly non-Hermitian, are contained in the union …

The paper is concerned with the spectral synthesis for general dissipative boundary value
problems for n× n first order systems of ordinary differential equations on a finite interval. We …

We consider the 1D Dirac operator on the half-line with compactly supported potentials. We
study resonances as the poles of scattering matrix or equivalently as the zeros of modified …