IJPAM: Volume 12, No. 1 (2004)

CHARACTERISTIC PROPERTIES FOR
INEQUALITIES IN HILBERT SPACES

C.-S. Lin
Department of Mathematics
Bishop's University
Lennoxville, Quebec, J1M 1Z7, CANADA
e-mail: plin@ubishops.ca


Dedicated to Professor Mao Sheng Chang
on his retirement.


Abstract.In this article we present some new inequalities in a Hilbert space which are equivalent to the Cauchy-Schwarz inequality. Altered forms of inequalities are given, and we provide necessary and sufficient conditions for equalities. In applications these inequalities will be used to obtain some inequalities of bounded linear operators (some of them are known) on a Hilbert space with considerable simplifications in the proofs.

Received: January 15, 2004

AMS Subject Classification: 47A63

Key Words and Phrases: Cauchy-Schwarz inequality, Bessel inequality, polar decomposition of an operator, Heinz inequality, Löwner-Heinz formula, Furuta inequality

Source: International Journal of Pure and Applied Mathematics
ISSN: 1311-8080
Year: 2004
Volume: 12
Issue: 1