On Quasi-Chebyshevity Subsets of Unital Banach Algebras

On Quasi-Chebyshevity Subsets of Unital Banach Algebras

Year:    2018

Analysis in Theory and Applications, Vol. 34 (2018), Iss. 1 : pp. 92–102

Abstract

In this paper, first, we consider closed convex and bounded subsets of infinite-dimensional unital Banach algebras and show with regard to the general conditions that these sets are not quasi-Chebyshev and pseudo-Chebyshev. Examples of those algebras are given including the algebras of continuous functions on compact sets. We also see some results in $\rm{C}^*$-algebras and Hilbert $\rm{C}^*$-modules. Next, by considering some conditions, we study Chebyshev of subalgebras in $\rm{C}^*$-algebras.

You do not have full access to this article.

Already a Subscriber? Sign in as an individual or via your institution

Journal Article Details

Publisher Name:    Global Science Press

Language:    English

DOI:    https://doi.org/10.4208/ata.2018.v34.n1.7

Analysis in Theory and Applications, Vol. 34 (2018), Iss. 1 : pp. 92–102

Published online:    2018-01

AMS Subject Headings:    Global Science Press

Copyright:    COPYRIGHT: © Global Science Press

Pages:    11

Keywords:    Best approximation Quasi-Chebyshev sets Pseudo-Chebyshev $\rm{C}^∗$-algebras Hilbert $\rm{C}^∗$-modules.