138 citations · 1.3k across the 90 of their papers we have counts for
6 papers · 2 filters
Spectral enclosures and stability for non-self-adjoint discrete Schroedinger operators on the half-line
David Krejcirik, Ari Laptev, Frantisek Stampach
We make a spectral analysis of discrete Schroedinger operators on the half-line, subject to complex Robin-type boundary couplings and complex-valued potentials. First, optimal spec…
Horizontal magnetic fields and improved Hardy inequalities in the Heisenberg group
Biagio Cassano, Valentina Franceschi, David Krejcirik +1
In this paper we introduce a notion of magnetic field in the Heisenberg group and we study its influence on spectral properties of the corresponding magnetic (sub-elliptic) Laplaci…
A sharp form of the discrete Hardy inequality and the Keller-Pinchover-Pogorzelski inequality
David Krejcirik, Frantisek Stampach
We give a short proof of a recently established Hardy-type inequality due to Keller, Pinchover, and Pogorzelski together with its optimality. Moreover, we identify the remainder te…
Localization of eigenvalues for non-self-adjoint Dirac and Klein-Gordon operators
Piero D'Ancona, Luca Fanelli, David Krejcirik +1
This note aims to give prominence to some new results on the absence and localization of eigenvalues for the Dirac and Klein-Gordon operators, starting from known resolvent estimat…
Spectral optimisation of Dirac rectangles
Philippe Briet, David Krejcirik
We are concerned with the dependence of the lowest positive eigenvalue of the Dirac operator on the geometry of rectangles, subject to infinite-mass boundary conditions. We conject…
Spectral properties of relativistic quantum waveguides
William Borrelli, Philippe Briet, David Krejcirik +1
We make a spectral analysis of the massive Dirac operator in a tubular neighborhood of an unbounded planar curve,subject to infinite mass boundary conditions. Under general assumpt…