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We prove a Lieb-Thirring type inequality for a complex perturbation of a d-dimensional massive Dirac operator $D_m, m\geq 0$ whose spectrum is $]-\infty , -m]\cup[m , +\infty[$. The difficulty of the study is that the unperturbed operator…

Spectral Theory · Mathematics 2013-12-04 Clément Dubuisson

We characterise regions in the complex plane that contain all non-embedded eigenvalues of a perturbed periodic Dirac operator on the real line with real-valued periodic potential and a generally non-symmetric matrix-valued perturbation V .…

Spectral Theory · Mathematics 2024-10-17 Ghada Shuker Jameel , Karl Michael Schmidt

We provide quantitative estimates on the location of eigenvalues of one-dimensional discrete Dirac operators with complex $\ell^p$-potentials for $1\leq p\leq\infty$. As a corollary, subsets of the essential spectrum free of embedded…

Spectral Theory · Mathematics 2020-08-25 Biagio Cassano , Orif O. Ibrogimov , David Krejcirik , Frantisek Stampach

We give general spectral and eigenvalue perturbation bounds for a selfadjoint operator perturbed in the sense of the pseudo-Friedrichs extension. We also give several generalisations of the aforementioned extension. The spectral bounds for…

Spectral Theory · Mathematics 2008-01-21 K. Veselic

This is mostly a survey paper, where we collect results concerning the spectral bounds of deterministic and random Schr\"odinger operators with complex potentials, both on \(\mathbb{R}^d\) and on compact manifolds. The survey part is…

Spectral Theory · Mathematics 2026-05-19 Eduard Stefanescu

We obtain a new bound on the location of eigenvalues for a non-self-adjoint Schr\"odinger operator with complex-valued potentials by obtaining a weighted $L^2$ estimate for the resolvent of the Laplacian.

Analysis of PDEs · Mathematics 2018-10-09 Yoonjung Lee , Ihyeok Seo

We study the trace class perturbations of the whole-line, discrete Laplacian and obtain a new bound for the perturbation determinant of the corresponding non-self-adjoint Jacobi operator. Based on this bound, we refine the Lieb--Thirring…

Spectral Theory · Mathematics 2021-01-07 Leonid Golinskii

We consider the 3-dimensional Stark operator perturbed by a complex-valued potential. We obtain an estimate for the number of eigenvalues of this operator as well as for the sum of imaginary parts of eigenvalues situated in the upper…

Spectral Theory · Mathematics 2018-04-17 Evgeny Korotyaev , Oleg Safronov

We study the behavior of the limit of the spectrum of a non self-adjoint Sturm-Liouville operator with analytic potential as the semi-classical parameter $h\to 0$. We get a good description of the spectrum and limit spectrum near $\infty$.…

Spectral Theory · Mathematics 2007-05-23 Nedelec Laurence

We prove Lieb-Thirring-type bounds for fractional Schr\"odinger operators and Dirac operators with complex-valued potentials. The main new ingredient is a resolvent bound in Schatten spaces for the unperturbed operator, in the spirit of…

Spectral Theory · Mathematics 2020-06-02 Jean-Claude Cuenin

The Lieb-Thirring inequalities give a bound on the negative eigenvalues of a Schr\"odinger operator in terms of an $L^p$ norm of the potential. This is dual to a bound on the $H^1$-norms of a system of orthonormal functions. Here we extend…

Mathematical Physics · Physics 2019-12-19 Rupert L. Frank , Mathieu Lewin , Elliott H. Lieb , Robert Seiringer

Let $H := H_{0} + V$ and $H_{\perp} := H_{0,\perp} + V$ be respectively perturbations of the free Schr\"odinger operators $H_{0}$ on $L^{2}\big(\mathbb{R}^{2d+1}\big)$ and $H_{0,\perp}$ on $L^{2}\big(\mathbb{R}^{2d}\big)$, $d \geq 1$ with…

Mathematical Physics · Physics 2013-12-10 Diomba Sambou

We derive quantitative bounds for eigenvalues of complex perturbations of the indefinite Laplacian on the real line. Our results substantially improve existing results even for real-valued potentials. For $L^1$-potentials, we obtain optimal…

Spectral Theory · Mathematics 2020-04-28 Jean-Claude Cuenin , Orif O. Ibrogimov

We analyze eigenvalues emerging from thresholds of the essential spectrum of one-dimensional Dirac operators perturbed by complex and non-symmetric potentials. In the general non-self-adjoint setting we establish the existence and…

Spectral Theory · Mathematics 2018-03-14 Jean-Claude Cuenin , Petr Siegl

We consider singular perturbed eigenvalue problem for Laplace operator in a cylinder with frequent and nonperiodic alternation of boundary conditions imposed on narrow strips lying in the lateral surface. The width of strips depends on a…

Mathematical Physics · Physics 2015-06-26 Denis I. Borisov

We study the spectrum of a system of second order differential operator perturbed by a non-selfadjoint matrix valued potential. We prove that eigenvalues of the perturbed operator are located near the edges of the spectrum of the…

Spectral Theory · Mathematics 2016-12-19 Francesco Ferrulli , Ari Laptev , Oleg Safronov

We derive sharp quantitative bounds for eigenvalues of biharmonic operators perturbed by complex-valued potentials in dimensions one, two and three.

Spectral Theory · Mathematics 2022-08-22 Orif O. Ibrogimov , David Krejcirik , Ari Laptev

We prove upper and lower bounds for sums of eigenvalues of Lieb-Thirring type for non-self-adjoint Schr\"odinger operators on the half-line. The upper bounds are established for general classes of integrable potentials and are shown to be…

Spectral Theory · Mathematics 2022-03-01 Leonid Golinskii , Alexei Stepanenko

We consider a second order self-adjoint operator in a domain which can be bounded or unbounded. The boundary is partitioned into two parts with Dirichlet boundary condition on one of them, and Neumann condition on the other. We assume that…

Spectral Theory · Mathematics 2018-09-28 Denis Borisov , Ivan Veselic'

We prove eigenvalue bounds for Schr\"odinger operator $-\Delta_g+V$ on compact manifolds with complex potentials $V$. The bounds depend only on an $L^q$-norm of the potential, and they are shown to be optimal, in a certain sense, on the…

Spectral Theory · Mathematics 2025-10-28 Jean-Claude Cuenin