Nontrivial isometries on sp(α)

sp(α) is a Banach space of sequences x with ‖x‖=(∑i=0∞|xi|p+α∑i=0∞|xi+1−xi|p)1/p. For 1<p<∞, p≠2, 0<α<∞, α≠1, there are no nontrivial surjective isometries in sp(α). It has been conjectured that there are no nontrivial isometries. This note gives two distinct counterexamples to this conj...

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Main Author: Stephen L. Campbell
Format: Article
Language:English
Published: Hindawi Limited 1982-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Subjects:
Online Access:http://dx.doi.org/10.1155/S0161171282000222
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spelling doaj-6c1840db4ced4d898e79d48077219db82020-11-24T23:01:34ZengHindawi LimitedInternational Journal of Mathematics and Mathematical Sciences0161-17121687-04251982-01-015225726110.1155/S0161171282000222Nontrivial isometries on sp(α)Stephen L. Campbell0Department of Mathematics, North Carolina State University, Raleigh 27650, North Carolina, USAsp(α) is a Banach space of sequences x with ‖x‖=(∑i=0∞|xi|p+α∑i=0∞|xi+1−xi|p)1/p. For 1<p<∞, p≠2, 0<α<∞, α≠1, there are no nontrivial surjective isometries in sp(α). It has been conjectured that there are no nontrivial isometries. This note gives two distinct counterexamples to this conjecture and a partial affirmative answer for the case of isometries with finite codimension.http://dx.doi.org/10.1155/S0161171282000222isometrysequential Banach spaceBanach space.
collection DOAJ
language English
format Article
sources DOAJ
author Stephen L. Campbell
spellingShingle Stephen L. Campbell
Nontrivial isometries on sp(α)
International Journal of Mathematics and Mathematical Sciences
isometry
sequential Banach space
Banach space.
author_facet Stephen L. Campbell
author_sort Stephen L. Campbell
title Nontrivial isometries on sp(α)
title_short Nontrivial isometries on sp(α)
title_full Nontrivial isometries on sp(α)
title_fullStr Nontrivial isometries on sp(α)
title_full_unstemmed Nontrivial isometries on sp(α)
title_sort nontrivial isometries on sp(α)
publisher Hindawi Limited
series International Journal of Mathematics and Mathematical Sciences
issn 0161-1712
1687-0425
publishDate 1982-01-01
description sp(α) is a Banach space of sequences x with ‖x‖=(∑i=0∞|xi|p+α∑i=0∞|xi+1−xi|p)1/p. For 1<p<∞, p≠2, 0<α<∞, α≠1, there are no nontrivial surjective isometries in sp(α). It has been conjectured that there are no nontrivial isometries. This note gives two distinct counterexamples to this conjecture and a partial affirmative answer for the case of isometries with finite codimension.
topic isometry
sequential Banach space
Banach space.
url http://dx.doi.org/10.1155/S0161171282000222
work_keys_str_mv AT stephenlcampbell nontrivialisometriesonspa
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