Open subgroups of G and almost periodic functionals on A(G)

Authors
Citation
Zg. Hu, Open subgroups of G and almost periodic functionals on A(G), P AM MATH S, 128(8), 2000, pp. 2473-2478
Citations number
11
Categorie Soggetti
Mathematics
Journal title
PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY
ISSN journal
00029939 → ACNP
Volume
128
Issue
8
Year of publication
2000
Pages
2473 - 2478
Database
ISI
SICI code
0002-9939(2000)128:8<2473:OSOGAA>2.0.ZU;2-P
Abstract
Let G be a locally compact group and let C-delta*(G) denote the C*-algebra generated by left translation operators on L-2(G). Let AP((G) over cap) and WAP((G) over cap) be the spaces of almost periodic and weakly almost perio dic functionals on the Fourier algebra A(G), respectively. It is shown that if G contains an open abelian subgroup, then (1) AP((G) over cap) = C-delt a*(G) if and only if AP((G) over cap)(c) is norm dense in AP((G) over cap); (2) WAP((G) over cap) is a C*-algebra if WAP((G) over cap)(c) is norm dens e in WAP((G) over cap), where X-c denotes the set of elements in X with com pact support. In particular, for any amenable locally compact group G which contains an open abelian subgroup, G has the dual Bohr approximation prope rty and WAP((G) over cap) is a C*-algebra.