ACTA issues

On the characterizations of some distinguished subclasses of Hilbert space operators

C. Bouraya, A. Seddik

Acta Sci. Math. (Szeged) 84:3-4(2018), 611-627

Abstract. In this note, we present several characterizations for some distinguished classes of bounded Hilbert space operators (self-adjoint operators, normal operators, unitary operators, and isometry operators) in terms of operator inequalities.

DOI: 10.14232/actasm-017-773-6

AMS Subject Classification (1991): 47A30, 47A05, 47B15

Keyword(s): closed range operator, Moore-Penrose inverse, group inverse, self-adjoint operator, unitary operator, normal operator, partial isometry operator, isometry operator, operator inequality

Received April 8, 2017, and in final form November 25, 2017. (Registered under 23/2017.)