There is constructed a compactly generated, separable, locally compact group G and a continuous irreducible unitary representation π of G such that the image π(C*(G)) of the group C*-algebra contains the algebra of compact operators, while the image of the -group algebra does not containany nonzero compact operator. The group G is a semidirect product of a metabelian discrete group and a “generalized Heisenberg group”.
@article{bwmeta1.element.bwnjournal-article-smv105i2p189bwm, author = {Detlev Poguntke}, title = {An example of a generalized completely continuous representation of a locally compact group}, journal = {Studia Mathematica}, volume = {104}, year = {1993}, pages = {189-205}, zbl = {0815.22002}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-smv105i2p189bwm} }
Poguntke, Detlev. An example of a generalized completely continuous representation of a locally compact group. Studia Mathematica, Tome 104 (1993) pp. 189-205. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-smv105i2p189bwm/
[00000] [1] J. Dixmier, Les C*-algèbres et leurs représentations, Gauthier-Villars, Paris 1969.
[00001] [2] Ph. Green, The structure of imprimitivity algebras, J. Funct. Anal. 36 (1980), 88-104. | Zbl 0422.46048
[00002] [3] A. Guichardet, Caractères des algèbres de Banach involutives, Ann. Inst. Fourier (Grenoble) 13 (1963), 1-81. | Zbl 0124.07003
[00003] [4] H. Leptin, Verallgemeinerte -Algebren und projektive Darstellungen lokal kompakter Gruppen, Invent. Math. 3 (1967), 257-281, 4 (1967), 68-86.
[00004] [5] H. Leptin and D. Poguntke, Symmetry and nonsymmetry for locally compact groups, J. Funct. Anal. 33 (1979), 119-134. | Zbl 0414.43004
[00005] [6] D. Poguntke, Unitary representations of Lie groups and operators of finite rank, Ann. of Math., to appear. | Zbl 0828.22013
[00006] [7] H. Reiter, Classical Harmonic Analysis and Locally Compact Groups, Clarendon, Oxford 1968. | Zbl 0165.15601