Sums of products of positive operators and spectra of Lüders operators

some properties of fuzzy hilbert spaces and norm of operators

in this thesis, at first we investigate the bounded inverse theorem on fuzzy normed linear spaces and study the set of all compact operators on these spaces. then we introduce the notions of fuzzy boundedness and investigate a new norm operators and the relationship between continuity and boundedness. and, we show that the space of all fuzzy bounded operators is complete. finally, we define...

The Sums and Products of Commuting AC-Operators

Abstract: In this paper, we exhibit new conditions for the sum of two commuting AC-operators to be again an AC-operator. In particular, this is satisfied on Hilbert space when one of them is a scalar-type spectral operator.  

Products of Positive Operators

A number of mathematicians have considered the problem of writing an operator as a product of \nice" operators, such as positive, hermitian or normal operators. Our principal reference for this is a paper of P.Y. Wu 6], but see also 2] and 5]. This kind of question, and related questions, have also been considered in a C*-algebra context, see 3]. A core result of Wu's paper is his theorem that ...

Spectra of Tensor Products of Operators

Stability of essential spectra of bounded linear operators

In this paper‎, ‎we show the stability of Gustafson‎, ‎Weidmann‎, ‎Kato‎, ‎Wolf‎, ‎Schechter and Browder essential spectrum of bounded linear operators on Banach spaces which remain invariant under additive perturbations‎ ‎belonging to a broad classes of operators $U$ such $gamma(U^m)