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19992026
most citedPseudospectra in non-Hermitian quantum mechanics

138 citations · 1.3k across the 90 of their papers we have counts for

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math.SP2025

Is the optimal magnetic rectangle a square?

David Krejcirik

We are concerned with the dependence of the lowest eigenvalue of the magnetic Dirichlet Laplacian on the geometry of rectangles, subject to homogeneous fields. We conjecture that t…

math.SP2024

Semiclassical asymptotics of the Bloch--Torrey operator in two dimensions

Frédéric Hérau, David Krejcirik, Nicolas Raymond

The Bloch--Torrey operator on a bounded smooth planar domain, subject to Dirichlet boundary conditions, is analyzed. Assuming an…

math.SP2023★ 1 cited

Criticality transition for positive powers of the discrete Laplacian on the half line

Borbala Gerhat, David Krejcirik, Frantisek Stampach

We study the criticality and subcriticality of powers with of the discrete Laplacian acting on . We prove that these positive powers of the…

math.SP2022★ 8 cited

An improved discrete Rellich inequality on the half-line

Borbala Gerhat, David Krejcirik, Frantisek Stampach

Based on a new idea of factorization, we prove an improved discrete Rellich inequality and discuss its optimality. We also give a conjecture on improved higher order discrete Hardy…

math.SP2022

Quasi-conical domains with embedded eigenvalues

David Krejcirik, Vladimir Lotoreichik

The spectrum of the Dirichlet Laplacian on any quasi-conical open set coincides with the non-negative semi-axis. We show that there is a connected quasi-conical open set such that…

math.SP2022

Spectrum of the wave equation with Dirac damping on a non-compact star graph

David Krejcirik, Julien Royer

We consider the wave equation on non-compact star graphs, subject to a distributional damping defined through a Robin-type vertex condition with complex coupling. It is shown that…