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Embedding Theorems in Group C*-Algebras

Published online by Cambridge University Press:  20 November 2018

Tan-Yu Lee*
Affiliation:
Department of Mathematics, University of AlabamaUniversity, AL 35486
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Abstract

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Let G be a locally compact group and H an open subgroup of G. The embeddings of group C*-algebras associated with H into the group C*-algebras associated with G are studied. Three conditions for the embeddings given in terms of C*-norms of the group algebras, group representations and positive definite functions are shown to be equivalent. As corollary, we prove that the full C*-algebra of H can be embedded into the full C*-algebra of G in a natural way as well as the case for the reduced group C*-algebras. We also show that the embeddings hold for their duals and double duals.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1983

Footnotes

This paper is essentially a generalization of some results in the author's Ph.D. thesis, written at the University of California, Santa Barbara, under the direction of Professor Charles A. Akemann.

References

1. Akemann, C. A., Operator algebras associated with Fuchsian groups, Houston Journal of Math., 7 (3) 1981 295301.Google Scholar
2. Akemann, C. A. and Lee, T.-Y., Some simple C*-algebras associated with free groups, Indiana Univ. Math. J., 29 (4) (1980), 505511.Google Scholar
3. Akemann, C. A. and Ostrand, P. A., Computing norms in group C*-algebras, Amer. J. Math., 98 (4) (1976), 10151047.Google Scholar
4. Akemann, C. A. and Ostrand, P. A., On a tensor product C*-algebra associated with the free group on two generators, J. Math. Soc. Japan 27 (4) (1975), 589599.Google Scholar
5. Choi, M. D., A simple C*-algebra generated by two finite-order unitaries, Canad. J. Math., 31 (1979), 867880.Google Scholar
6. Choi, M. D., The full C*-algebra of the free group on two generators, Pac. J. Math., 87 (1) (1980), 4147.Google Scholar
7. Choi, M. D. and Effros, E., Lifting problems and the cohomology of C*-algebras, Canad. J. Math., 29 (1977), 10921111.Google Scholar
8. Diximier, J., Les C*-algebras et leurs representations, Gauthier-Villars, Paris, 1969.Google Scholar
9. Ernest, J., A new group algebra for locally compact groups I, Amer. J. Math., 86 (1964), 467492.Google Scholar
10. Eymard, P., L'alg?bre de Fourier d'un groupe localement compact. Bull. Soc. Math. France 92 (1964), 181236.Google Scholar
11. Fell, J. M. G., Weak containment and induced representations of groups, Canad. J. Math. 14 (1962), 237268.Google Scholar
12. Fell, J. M. G., The dual spaces of C*-algebras, Trans. Amer. Math. Soc. 94 (1960), 365403.Google Scholar
13. Hewitt, E. and Ross, K. A., Abstract Harmonic Analysis, I & II, Springer-Verlag, 1963 & 1970.Google Scholar
14. Mackey, G., The theory of group representation, Univ. of Chicago notes, 1955.Google Scholar
15. Pontryagin, L. S., Topological groups (translated by Arlen Brown), 2nd edition, Gordon and Breach Science Publishers, Inc., 1966.Google Scholar
16. Paschke, W. L. and Salinas, N., C*-algebras associated with free products of groups, Pac. J. Math., 82 (1979), 211221.Google Scholar
17. Rickart, C., General Theory of Banach Algebras, Van Nostrand, New York, 1960.Google Scholar
18. Sakai, S., C*-algebras and W*-algebras, Springer-Verlag, 1971.Google Scholar
19. Tomiyama, J., On the projection of norm 1 in W*-algebra, Proc. Japan Acad. 33 (1957), 608612.Google Scholar
20. Wassermann, S., On tensor products of certain group C*-algebras, J. Funct. Anal. 23 (1976), 238254.Google Scholar