Economical Finite Rank Perturbations of Semi-Fredholm Operators.
Ein neues Surjektivitätskriterium im Hilbertraum.
Ein Störungssatz für abgeschlossene, lineare Operatoren.
Ein Zerlegungssatz für Resolventen elliptischer Operatoren.
Eine Bemerkung zur Division von Distributionen durch analytische Operatorfunktionen.
Eine Existenzausgabe für asymptotisch lineare Störungen eines Fredholmoperators mit Index 0.
Erratum to "Stability of the index of a linear relation under compact perturbations" (Studia Math. 180 (2007), 95-102)
We give a corrected version of the main result from the paper cited in the title. We obtain necessary and sufficient conditions for the stability of the topological index of an open linear relation under compact perturbations
Essential descent spectrum and commuting compact perturbations.
Essential spectra of quasisimilar -quasihyponormal operators.
Étude d'une fonction remarquable associée aux moyennes de convolution
Dans cet article nous étudions la série génératrice des poids alternés d’une moyenne de convolution induite par un processus de diffusion. Nous montrons que celle-ci est une fonction méromorphe, naturellement liée à un certain opérateur compact. Cette fonction est simplement égale à , lorsque le déterminant de Fredholm de cet opérateur existe, et nous la précisons dans les autres cas.
Every nilpotent operator fails to determine the complete norm topology.
Examples of infinite dimensional isoparametric submanifolds.
Extended Weyl type theorems
An operator acting on a Banach space possesses property if where is the approximate point spectrum of , is the essential semi-B-Fredholm spectrum of and is the set of all isolated eigenvalues of In this paper we introduce and study two new properties and in connection with Weyl type theorems, which are analogous respectively to Browder’s theorem and generalized Browder’s theorem. Among other, we prove that if is a bounded linear operator acting on a Banach space , then...
Extremal perturbations of semi-Fredholm operators
Let T be a bounded operator on an infinite-dimensional Banach space X and Ω a compact subset of the semi-Fredholm domain of T. We construct a finite rank perturbation F such that min[dim N(T+F-λ), codim R(T+F-λ)] = 0 for all λ ∈ Ω, and which is extremal in the sense that F² = 0 and rank F = max{min[dim N(T-λ), codim R(T-λ)] : λ ∈ Ω.