International Journal of Mathematics and Mathematical Sciences
Volume 25 (2001), Issue 2, Pages 129-133
doi:10.1155/S0161171201004458
Some inequalities in B(H)
C. Duyar1
and H. Seferoglu2
1University of Ondokuz Mayis, Faculty of Art and Sciences, Department of Mathematics, Samsun, Turkey
2100. Yil University, Faculty of Education, Department of Mathematics, Van, Turkey
Abstract
Let H denote a separable Hilbert space and let B(H) be the space of bounded and linear operators from H to H. We define a subspace Δ(A,B) of B(H), and prove two inequalities between the distance to Δ(A,B) of each operator T in B(H), and the value sup{‖AnTBn−T‖:n=1,2,…}.