Bull. Austral. Math. Soc. 72(2) pp.299--315, 2005.
Proper 1-ball
contractive retractions in
Banach spaces of measurable functions
D. Caponetti |
A. Trombetta |
G. Trombetta |
.
Abstract
In this paper we consider the Wośko problem
of evaluating, in an infinite-dimensional Banach space X, the infimum of all k
1 for which there exists a
k-ball contractive retraction of
the unit ball onto its boundary. We prove that in some classical
Banach spaces the best possible value 1
is attained. Moreover we give estimates of the lower H-measure of
noncompactness of the retractions we construct.
1 for which there exists a
k-ball contractive retraction of
the unit ball onto its boundary. We prove that in some classical
Banach spaces the best possible value 1
is attained. Moreover we give estimates of the lower H-measure of
noncompactness of the retractions we construct.Click to download PDF of this article (free access until July 2006)
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[an error occurred while processing this directive]| (Metadata: XML, RSS, BibTeX) | MathSciNet: MR2183411 | Z'blatt-MATH: 02246392 |
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