Assume X is an infinite dimensional F-normed space and let r be a positive number such that the closed ball Br(X) of radius r is properly contained in X. The main aim of this paper is to give examples of regular F-normed ideal spaces in which there is a 1-ball or(1 + ε)-ball contractive retraction of Br(X) onto its boundary with positive lower Hausdorff measure of noncompactness. The examples are based on the abstract results of the paper, obtained under suitable hypotheses on X.

Examples of proper k-ball contractive retractions in F-normed spaces

CAPONETTI D;TROMBETTA A;TROMBETTA G
2007-01-01

Abstract

Assume X is an infinite dimensional F-normed space and let r be a positive number such that the closed ball Br(X) of radius r is properly contained in X. The main aim of this paper is to give examples of regular F-normed ideal spaces in which there is a 1-ball or(1 + ε)-ball contractive retraction of Br(X) onto its boundary with positive lower Hausdorff measure of noncompactness. The examples are based on the abstract results of the paper, obtained under suitable hypotheses on X.
2007
regular F-normed ideal space, retraction, k-ball contraction
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11770/159036
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