Displaying similar documents to “Some new properties in Fredholm theory, Schechter essential spectrum, and application to transport theory.”

A characterization of the essential spectrum and applications

Aref Jeribi (2002)

Bollettino dell'Unione Matematica Italiana

Similarity:

In this article the essential spectrum of closed, densely defined linear operators is characterized on a large class of spaces, which possess the Dunford-Pettis property or which isomorphic to one of the spaces L p ⁢ Ω p > 1 . A practical criterion guaranteeing its stability, for perturbed operators, is given. Further we apply the obtained results to investigate the essential spectrum of one-dimensional transport equation with general boundary conditions. Finally, sufficient conditions...

The Słodkowski spectra and higher Shilov boundaries

Vladimír Müller (1993)

Studia Mathematica

Similarity:

We investigate relations between the spectra defined by Słodkowski [14] and higher Shilov boundaries of the Taylor spectrum. The results generalize the well-known relation between the approximate point spectrum and the usual Shilov boundary.

Note on operational quantities and Mil'man isometry spectrum.

Manuel González, Antonio Martinón (1991)

Extracta Mathematicae

Similarity:

Let X and Y be infinite dimensional Banach spaces and let L(X,Y) be the class of all (linear continuous) operators acting between X and Y. Mil'man [5] introduced the isometry spectrum I(T) of T ∈ L(X,Y) in the following way: I(T) = {α ≥ 0: ∀ ε > 0, ∃M ∈ S∞(X), ∀x ∈ SM, | ||Tx|| - α | < ε}}, where S∞(X) is the set of all infinite dimensional closed subspaces of X and S...

On the axiomatic theory of spectrum

V. Kordula, V. Müller (1996)

Studia Mathematica

Similarity:

There are a number of spectra studied in the literature which do not fit into the axiomatic theory of Żelazko. This paper is an attempt to give an axiomatic theory for these spectra, which, apart from the usual types of spectra, like one-sided, approximate point or essential spectra, include also the local spectra, the Browder spectrum and various versions of the Apostol spectrum (studied under various names, e.g. regular, semiregular or essentially semiregular).