Abstract. We consider a general framework for investigating spectral pollu-tion in the Galerkin method. We show how this phenomenon is characterised via the existence of particular Weyl sequences which are singular in a suitable sense. For a semi-bounded selfadjoint operator A we identify relative com-pactness conditions on a selfadjoint perturbation B ensuring that the limiting set of spectral pollution of A and B coincide. Our results show that, under perturbation, this limiting set behaves in a similar fashion as the essential spectrum. Content
Abstract. “Weyl’s theorem ” for an operator on a Hilbert space is a statement that the com-plement i...
AbstractIt is shown that ifTis a dominant operator or an analytic quasi-hyponormal operator on a com...
International audienceThe asymptotic distribution of eigenvalues of self-adjoint differential operat...
The new version deals with Galerkin sequences which are dense in the form domain of A, when A is bou...
We consider the Galerkin method for approximating the spectrum of an operator T+A where T is semi-bo...
International audienceThis paper, devoted to the study of spectral pollution, contains both abstract...
In 1909 H. Weyl [59] studied the spectra of all compact linear perturbations of a self-adjoint opera...
This thesis is concerned with the extension of classical Titchmarsh-Weyl theory to non-selfadjoint S...
The essential spectrum of the singular matrix differential operator of mixed order determined by the...
The qualitative properties of perturbed differential equations are investigated. The analogies of th...
This open access book presents a comprehensive survey of modern operator techniques for boundary val...
A bounded operator T in L(X) acting on a Banach space X is said to satisfy generalized Weyl's theore...
The notion of second-order relative spectrum of a self-adjoint operator acting on a Hilbert space ha...
The Spectral Theorem for Self-Adjoint Operators allows one to define what it means to evaluate a fun...
Abstract. We develop Weyl–Titchmarsh theory for Schrödinger operators with strongly singular potent...
Abstract. “Weyl’s theorem ” for an operator on a Hilbert space is a statement that the com-plement i...
AbstractIt is shown that ifTis a dominant operator or an analytic quasi-hyponormal operator on a com...
International audienceThe asymptotic distribution of eigenvalues of self-adjoint differential operat...
The new version deals with Galerkin sequences which are dense in the form domain of A, when A is bou...
We consider the Galerkin method for approximating the spectrum of an operator T+A where T is semi-bo...
International audienceThis paper, devoted to the study of spectral pollution, contains both abstract...
In 1909 H. Weyl [59] studied the spectra of all compact linear perturbations of a self-adjoint opera...
This thesis is concerned with the extension of classical Titchmarsh-Weyl theory to non-selfadjoint S...
The essential spectrum of the singular matrix differential operator of mixed order determined by the...
The qualitative properties of perturbed differential equations are investigated. The analogies of th...
This open access book presents a comprehensive survey of modern operator techniques for boundary val...
A bounded operator T in L(X) acting on a Banach space X is said to satisfy generalized Weyl's theore...
The notion of second-order relative spectrum of a self-adjoint operator acting on a Hilbert space ha...
The Spectral Theorem for Self-Adjoint Operators allows one to define what it means to evaluate a fun...
Abstract. We develop Weyl–Titchmarsh theory for Schrödinger operators with strongly singular potent...
Abstract. “Weyl’s theorem ” for an operator on a Hilbert space is a statement that the com-plement i...
AbstractIt is shown that ifTis a dominant operator or an analytic quasi-hyponormal operator on a com...
International audienceThe asymptotic distribution of eigenvalues of self-adjoint differential operat...