8 papers
Optimal discrete -Hardy-Rellich-Birman inequalities
František Štampach, Jakub Waclawek
We present a theory for constructing optimal lower bounds for the discrete half-line -Laplacian of higher order and general . The abstract framework int…
The -Hardy-Rellich-Birman inequalities on the half-line
František Štampach, Jakub Waclawek
The classical discrete -Hardy inequality establishes a sharp relationship between the -norms of a sequence and its discrete derivative. In this paper, we generalize th…
Schrödinger operators on the half-line with integrable complex potentials
Alexander Pushnitski, František Štampach
In our previous work, we introduced the concept of a \emph{spectral pair} for a half-line Schrödinger operator with a \emph{complex} bounded potential , serving as a substitute…
Ratio asymptotics and zero density for orthogonal polynomials with varying Verblunsky coefficients
Rostyslav Kozhan, František Štampach
We study asymptotic behavior of orthogonal polynomials on the unit circle with varying Verblunsky coefficients when the ratio converges as . First, w…
The Borg-Marchenko uniqueness theorem for complex potentials
Alexander Pushnitski, František Štampach
We introduce and study a new theoretical concept of \textit{spectral pair} for a Schrödinger operator in with a bounded \textit{complex-valued} potential…
A Herglotz-Nevanlinna function from the optimal discrete -Hardy weight
František Štampach, Jakub Waclawek
It was recently proved by Fischer, Keller, and Pogorzelski in [Integr. Equ. Oper. Theory, 95(24), 2023] that the classical discrete -Hardy inequality admits an improvement, and…