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This work is devoted to the asymptotic behavior of eigenvalues of an elliptic operator with rapidly oscillating random coefficients on a bounded domain with Dirichlet boundary conditions. A sharp convergence rate is obtained for isolated…

Analysis of PDEs · Mathematics 2022-05-18 Mitia Duerinckx

We study the asymptotic behaviour of eigenvalues and eigenfunctions of a boundary value problem for the Sturm-Liouville operator with general boundary conditions and the weight function perturbed by the so-called $\delta'$-like sequence…

Spectral Theory · Mathematics 2025-04-23 Yuriy Golovaty

We derive bounds on the location of non-embedded eigenvalues of Dirac operators on the half-line with non-Hermitian $L^1$-potentials. The results are sharp in the non-relativistic or weak-coupling limit. In the massless case, the absence of…

Spectral Theory · Mathematics 2013-11-27 Jean-Claude Cuenin

We prove optimal Lieb-Thirring type inequalities for Schr\"odinger and Jacobi operators with complex potentials. Our results bound eigenvalue power sums (Riesz means) by the $L^p$ norm of the potential, where in contrast to the self-adjoint…

Spectral Theory · Mathematics 2025-10-03 Sabine Bögli , Sukrid Petpradittha

Let $H_0$ be a purely absolutely continuous selfadjoint operator acting on some separable infinite-dimensional Hilbert space and $V$ be a compact non-selfadjoint perturbation. We relate the regularity properties of $V$ to various spectral…

Spectral Theory · Mathematics 2020-05-22 Olivier Bourget , Diomba Sambou , Amal Taarabt

We prove general comparison theorems for eigenvalues of perturbed Schrodinger operators that allow proof of Lieb--Thirring bounds for suitable non-free Schrodinger operators and Jacobi matrices.

Spectral Theory · Mathematics 2009-11-13 Rupert L. Frank , Barry Simon , Timo Weidl

The spectrum of the singular indefinite Sturm-Liouville operator $$A=\text{\rm sgn}(\cdot)\bigl(-\tfrac{d^2}{dx^2}+q\bigr)$$ with a real potential $q\in L^1(\mathbb R)$ covers the whole real line and, in addition, non-real eigenvalues may…

Spectral Theory · Mathematics 2017-12-19 Jussi Behrndt , Philipp Schmitz , Carsten Trunk

We study to what extent Lieb--Thirring inequalities are extendable from self-adjoint to general (possibly non-self-adjoint) Jacobi and Schr\"{o}dinger operators. Namely, we prove the conjecture of Hansmann and Katriel from [Complex Anal.…

Spectral Theory · Mathematics 2020-04-22 Sabine Bögli , František Štampach

We obtain weighted $L^2$ estimates for the elastic wave equation perturbed by singular potentials including the inverse-square potential. We then deduce the Strichartz estimates under the sole ellipticity condition for the Lam\'e operator…

Analysis of PDEs · Mathematics 2020-08-25 Seongyeon Kim , Yehyun Kwon , Ihyeok Seo

We discuss the eigenvalues $E_j$ of Schr\"odinger operators $-\Delta+V$ in $L^2(\mathbb R^d)$ with complex potentials $V\in L^p$, $p<\infty$. We show that (A) $\mathrm{Re} E_j\to\infty$ implies $\mathrm{Im} E_j\to 0$, and (B) $\mathrm{Re}…

Spectral Theory · Mathematics 2015-10-13 Rupert L. Frank

This paper is devoted to a general min-max characterization of the eigenvalues in a gap of the essential spectrum of a self-adjoint unbounded operator. We prove an abstract theorem, then we apply it to the case of Dirac operators with a…

Spectral Theory · Mathematics 2022-06-14 Jean Dolbeault , Maria J. Esteban , Eric Séré

In this paper we provide some more details on the numerical analysis and we present some enlightening numerical results related to the spectrum of a finite element least-squares approximation of the linear elasticity formulation introduced…

Numerical Analysis · Mathematics 2022-02-22 Linda Alzaben , Fleurianne Bertrand , Daniele Boffi

We consider eigenvalue sums of Schr\"odinger operators $-\Delta+V$ on $L^2(\R^d)$ with complex radial potentials $V\in L^q(\R^d)$, $q<d$. We prove quantitative bounds on the distribution of the eigenvlaues in terms of the $L^q$ norm of $V$.…

Spectral Theory · Mathematics 2024-09-06 Jean-Claude Cuenin , Solomon Keedle-Isack

We study the discrete eigenvalues emerging from the threshold of the essential spectrum of one or two-dimensional Schr\"odinger operators with complex-valued $ L^p $-potentials in a weak coupling regime. We derive necessary and sufficient…

Spectral Theory · Mathematics 2025-12-02 Jussi Behrndt , Markus Holzmann , Petr Siegl , Nicolas Weber

Schr\"odinger operator on half-line with complex potential and the corresponding evolution are studied within perturbation theoretic approach. The total number of eigenvalues and spectral singularities is effectively evaluated. Wave…

Spectral Theory · Mathematics 2014-03-03 S. A. Stepin

We establish Lieb-Thirring power bounds on discrete eigenvalues of Jacobi operators for Schatten class perturbations under very general assumptions. Our results apply, in particular, to perturbations of reflectionless Jacobi operators with…

Spectral Theory · Mathematics 2017-09-25 Jacob S. Christiansen , Maxim Zinchenko

The goal of this note is to study the spectrum of a self-adjoint convolution operator in $L^2(\mathbb R^d)$ with an integrable kernel that is perturbed by an essentially bounded real-valued potential tending to zero at infinity. We show…

Spectral Theory · Mathematics 2023-11-16 Denis Borisov , Andrey Piatnitski , Elena Zhizhina

We show that the absolute values of non-positive eigenvalues of Schr\"odinger operators with complex potentials can be bounded in terms of L_p-norms of the potential. This extends an inequality of Abramov, Aslanyan, and Davies to higher…

Spectral Theory · Mathematics 2014-02-26 Rupert L. Frank

We consider the Landau Hamiltonian perturbed by a long-range electric potential $V$. The spectrum of the perturbed operator consists of eigenvalue clusters which accumulate to the Landau levels. First, we obtain an estimate of the rate of…

Spectral Theory · Mathematics 2015-06-16 Tomas Lungenstrass , Georgi Raikov

The paper considers the general form of self-adjoint boundary value problems for momentum operators with nonlocal potentials. We give an analysis of the eigenvalue distribution as zeros of the characteristic functions, for which their…

Functional Analysis · Mathematics 2025-12-15 Kamila Dębowska , Irina L. Nizhnik