IMPROVING BOUNDS FOR GENERALIZED BEREZIN NUMBER OF OPERATORS


Khan S., Akram M. S., GÜRDAL M.

Proceedings of the Institute of Mathematics and Mechanics, vol.51, no.2, pp.171-191, 2025 (ESCI, Scopus)

Abstract

This paper introduces an improvement of the Cauchy-Schwarz inequality in a semi-Hilbertian space with the inner product induced by an A-positive operator. This improved A-Cauchy-Schwarz inequality is then used to improve the bounds of the A-Berezin number of operators. First, we present upper bounds for the A-Berezin number of the product of two operators. Then, A-Berezin number bounds for the sum of two operators are developed. This work refines and extends some of the A-Berezin inequalities previously established in the literature.