Linear Operators and Their Essential Pseudospectra provides a comprehensive study of
spectral theory of linear operators defined on Banach spaces. The central items of interest in …

The concept of the line graph of a given graph is so natural that it has been independently
discovered by many authors. Of course, each author gave it a different name: It was called …

In this paper, we will determine some decomposition for matrix pencils multivalued linear
operator. Furthermore, we investigate the S-essential approximate point spectrum and the S …

S-essential spectra and measure of noncompactness Skip to content Should you have
institutional access? Here's how to get it ... De Gruyter € EUR - Euro £ GBP - Pound $ USD …

We study some properties and results on the S-Jeribi essential spectrum of linear bounded
operators on a Banach space. In particular, we give some criteria for coincidence of this …

The main goal of this paper, is to extend the concept of condition pseudospectrum to the
case of closed linear relations pencils and to reveal some of their properties. We will start by …

In the first part of this paper we show that, under some conditions, a polynomially
demicompact operator can be demicompact. An example involving the Caputo fractional …

In this article, we introduce the notion of polynomial demicompactness and we use it to give
some results on Fredholm operators and to establish a fine description of some essential …

In this paper, we study a detailed treatment of some subsets of M-essential spectra of closed
linear operators subjected to additive perturbations not necessarily belonging to any ideal of …

We begin this chapter by presenting the background material that is needed in our work.
Most of this background is drawn from functional analysis and operator theory by giving …