COMPACTIFICATIONS OF LOCALLY COMPACT-GROUPS AND QUOTIENTS

Citation
At. Lau et al., COMPACTIFICATIONS OF LOCALLY COMPACT-GROUPS AND QUOTIENTS, Mathematical proceedings of the Cambridge Philosophical Society, 116, 1994, pp. 451-463
Citations number
21
Categorie Soggetti
Mathematics, General",Mathematics
ISSN journal
03050041
Volume
116
Year of publication
1994
Part
3
Pages
451 - 463
Database
ISI
SICI code
0305-0041(1994)116:<451:COLCAQ>2.0.ZU;2-2
Abstract
Let N be a compact normal subgroup of a locally compact group G. One o f our goals here is to determine when and how a given compactification Y of G/N can be realized as a quotient of the analogous compactificat ion (psi, X) of G by N(psi) = psi(N) subset-of X; this is achieved in a number of cases for which we can establish that muN(psi) subset-of N (psi)mu for all mu is-an-element-of X. A question arises naturally, 'C an the latter containment be proper?' With an example, we give a posit ive answer to this question. The group G is an extension of N by G/N a nd can be identified algebraically with N x G/N when this product is g iven the Schreier multiplication, and for our further results we assum e that we can also identify G topologically with N x G/N. When G/N is discrete and X is the compactification of G coming from the left unifo rmly continuous functions, we are able to show that X is an extension of N by beta(G/N) (X congruent-to N x beta (G/N)) even when G is not a semidirect product. Examples are given to illustrate the theory, and also to show its limitations.