6 papers
Resolvent estimates for one-dimensional Dirac operators with imaginary potentials
Antonio Arnal, Tho Nguyen Duc, Petr Siegl
We investigate massive one-dimensional Dirac operators perturbed by diagonal matrix potentials of the form where the function is real-valued and unbounded at infinity. Fo…
Riesz property in the case of multiple eigenvalues
Boris Mityagin, Petr Siegl
We analyze spectra and the Riesz property of spectral projections of non-symmetric perturbations of self-adjoint operators with eigenvalues having arbitrary multiplicities, includi…
Revisiting the Weak Coupling Phenomenon for Two-Dimensional Schrödinger Operators
Jussi Behrndt, Petr Siegl, Nicolas Weber
We study the existence of negative eigenvalues for two-dimensional Schrödinger operators with real-valued potentials in the weak coupling regime. In his pioneering paper [Simon 19…
Semigroup decay for the wave equation with unbounded damping
Antonio Arnal, Borbala Gerhat, Julien Royer +1
We study the damped wave equation with a damping coefficient which is possibly singular and unbounded at infinity. In general, zero belongs to the spectrum of the corresponding gen…
Weak coupling for Schrödinger operators with complex potentials
Jussi Behrndt, Markus Holzmann, Petr Siegl +1
We study the discrete eigenvalues emerging from the threshold of the essential spectrum of one or two-dimensional Schrödinger operators with complex-valued -potentials in a…
Generalized boundary triples for adjoint pairs with applications to non-self-adjoint Schrödinger operators
Antonio Arnal, Jussi Behrndt, Markus Holzmann +1
We extend the notion of generalized boundary triples and their Weyl functions from extension theory of symmetric operators to adjoint pairs of operators, and we provide criteria on…