Classes of operators related to 2-isometric operators

Isometric weighted composition operators

A composition operator is an operator on a space of functions defined on the same set. Its action is by composition to the right with a fixed selfmap of that set. A composition operator followed by a multiplication operator is called a weighted composition operator. In this paper, we study when weighted composition operators on the Hilbert Hardy space of the open unit disc are isometric. We fin...

Some equivalence classes of operators on B(H)

induced operators on symmetry classes of polynomials

‎in this paper‎, ‎we give a necessary and sufficient condition for the equality of two symmetrized decomposable polynomials‎. ‎then‎, ‎we study some algebraic and geometric properties of the induced operators over symmetry classes of polynomials in the case of linear characters‎.

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...

Classes of admissible functions associated with certain integral operators applied to meromorphic functions

‎In the present paper‎, ‎by making use of the differential subordination and‎ ‎superordination results of Miller and Mocanu‎, ‎  ‎certain classes of admissible functions ‎are determined so that subordination as well as superordination implications‎ ‎of functions associated with an integral operator hold‎. ‎Additionally‎, ‎differential sandwich-type result is obtained‎.