Spectral synthesis and topologies on ideal spaces for Banach *-algebras

This paper continues the study of spectral synthesis and the topologies τ∞ and τr on the ideal space of a Banach algebra, concentrating on the class of Banach *-algebras, and in particular on L1-group algebras. It is shown that if a group G is a finite extension of an abelian group then τr is Hausdo...

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Main Authors: Feinstein, Joel, Kaniuth, E., Somerset, D.W.B.
Format: Article
Published: Elsevier 2002
Online Access:https://eprints.nottingham.ac.uk/15/
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author Feinstein, Joel
Kaniuth, E.
Somerset, D.W.B.
author_facet Feinstein, Joel
Kaniuth, E.
Somerset, D.W.B.
author_sort Feinstein, Joel
building Nottingham Research Data Repository
collection Online Access
description This paper continues the study of spectral synthesis and the topologies τ∞ and τr on the ideal space of a Banach algebra, concentrating on the class of Banach *-algebras, and in particular on L1-group algebras. It is shown that if a group G is a finite extension of an abelian group then τr is Hausdorff on the ideal space of L1(G) if and only if L1(G) has spectral synthesis, which in turn is equivalent to G being compact. The result is applied to nilpotent groups, [FD]−-groups, and Moore groups. An example is given of a non-compact, non-abelian group G for which L1(G) has spectral synthesis. It is also shown that if G is a non-discrete group then τr is not Hausdorff on the ideal lattice of the Fourier algebra A(G).
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spelling nottingham-152020-05-04T16:25:41Z https://eprints.nottingham.ac.uk/15/ Spectral synthesis and topologies on ideal spaces for Banach *-algebras Feinstein, Joel Kaniuth, E. Somerset, D.W.B. This paper continues the study of spectral synthesis and the topologies τ∞ and τr on the ideal space of a Banach algebra, concentrating on the class of Banach *-algebras, and in particular on L1-group algebras. It is shown that if a group G is a finite extension of an abelian group then τr is Hausdorff on the ideal space of L1(G) if and only if L1(G) has spectral synthesis, which in turn is equivalent to G being compact. The result is applied to nilpotent groups, [FD]−-groups, and Moore groups. An example is given of a non-compact, non-abelian group G for which L1(G) has spectral synthesis. It is also shown that if G is a non-discrete group then τr is not Hausdorff on the ideal lattice of the Fourier algebra A(G). Elsevier 2002-12-01 Article NonPeerReviewed Feinstein, Joel, Kaniuth, E. and Somerset, D.W.B. (2002) Spectral synthesis and topologies on ideal spaces for Banach *-algebras. Journal of Functional Analysis, 196 (1). pp. 19-39. ISSN 0022-1236 http://www.sciencedirect.com/science/article/pii/S0022123602939649 doi:10.1006/jfan.2002.3964 doi:10.1006/jfan.2002.3964
spellingShingle Feinstein, Joel
Kaniuth, E.
Somerset, D.W.B.
Spectral synthesis and topologies on ideal spaces for Banach *-algebras
title Spectral synthesis and topologies on ideal spaces for Banach *-algebras
title_full Spectral synthesis and topologies on ideal spaces for Banach *-algebras
title_fullStr Spectral synthesis and topologies on ideal spaces for Banach *-algebras
title_full_unstemmed Spectral synthesis and topologies on ideal spaces for Banach *-algebras
title_short Spectral synthesis and topologies on ideal spaces for Banach *-algebras
title_sort spectral synthesis and topologies on ideal spaces for banach *-algebras
url https://eprints.nottingham.ac.uk/15/
https://eprints.nottingham.ac.uk/15/
https://eprints.nottingham.ac.uk/15/