A Diaz--Metcalf type inequality for positive linear maps and its applications

M. S. Moslehian, R. Nakamoto, Y. Seo

We present a Diaz--Metcalf type operator inequality as a reverse Cauchy-Schwarz inequality and then apply it to get the operator versions of Pólya-Szegö's, Greub-Rheinboldt's, Kant…