© 1993 by London Mathematical Society
On the Spectrum of L
(G)
University of Alberta Edmonton Alberta Canada T6G 2G1
Teacher Training University Tehran 49 Mofateh Avenue Tehran Iran
University of Sheffield Sheffield S3 7RH
Received 3 October 1991. Revision received 28 February 1992.
We investigate the algebraic structure of the spectrum
of L
(G) for a locally compact group G. In contrast to the compact and discrete cases, when G has neither of these properties,
is never a semigroup. For
compact G we determine exactly when the product of two elements of
. is in
, but we present an example which suggests that for general groups the underlying set theory may have an effect. Our principal tool, which has independent interest, is a topological structure theorem for the LB-compactification of an arbitrary locally compact group.