Quasi-similarity and spectra of some classes of operators in hilbert spaces

Abstract

This thesis is devoted to results on spectrum and Cl operators. In the study of operator in Hilbert spaces, spectrum is important since it enables us achieve properties like normality, similarity, quasi-similarity, uniticity, unitarily equivalent, semi-similarity, log-hypo normality, class-A etc on operators which at first glance do not seem to behave as such. More specifically we delve into study through the following specific objectives: Review of spectrum in finite dimensional spaces locate spectrum of dominant operators and their subclasses, investigate relationship between quasi-similarity ai?:crspectrum of operators, investigate spectral properties of CI operators