Journal of Inequalities and Applications 
Volume 1 (1997), Issue 4, Pages 327-334
doi:10.1155/S1025583497000222

The best possibility of the bound for the Kantrovich inequality and some remarks

M. Tsukada1 and Sin-El Takahasi2

 1Department of Information Sciences, Toho University, Funabashi, Chiba 274, Japan
2Department of Basic Technology, Applied Mathematics and Physics, Yamagata University, Yonezawa, Yamagata 992, Japan
Received 1 November 1996

Abstract

The necessary and sufficient condition for equality to be attaind in the Kantrovich inequality is given and applied to an inequality of normal operators on Hilbert spaces.