norm of inverse of a bounded operator

Question

Are there any conditions in which norm of inverse of a bounded operator T is equal to reciprocal of norm of the operator T.

Answered at http://math.stackexchange.com/q/525970/1424. T must be a scalar multiple of an isometry. — Jonas Meyer, Oct 17 '14 at 11:40

score 0 · Answer 1 · answered Oct 17 '14 at 11:35

0

For example $T$ is similarity that is $||T(x)|| =s||x||$ for $x\in X.$

answered Oct 17 '14 at 11:35

1 Answers1