We give a new upper bound of the optimal retraction constant for innite dimensional cut invariant subspaces of B(K); in particular, we improve the previous estimate for the space ℓ1. Then we improve an old upper bound for the function of minimal displacement type, obtained by Goebel in 1973, in the case of an innite dimensional Hilbert space.
The minimal displacement and optimal retraction problems in some Banach spaces
CASINI, EMANUELE GIUSEPPE
2017-01-01
Abstract
We give a new upper bound of the optimal retraction constant for innite dimensional cut invariant subspaces of B(K); in particular, we improve the previous estimate for the space ℓ1. Then we improve an old upper bound for the function of minimal displacement type, obtained by Goebel in 1973, in the case of an innite dimensional Hilbert space.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.