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Compact Almost Discrete Hypergroups

Published online by Cambridge University Press:  20 November 2018

Michael Voit*
Affiliation:
Mathematisches Institut Technische Universität München Arcisstr.21 80333 München, Germany, e-mail: voit@mathematik.tu-muenchen.de
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Abstract

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A compact hypergroup is called almost discrete if it is homeomorphic to the one-point-compactification of a countably infinite discrete set. If the group Up of all p-adic units acts multiplicatively on the p-adic integers, then the associated compact orbit hypergroup has this property. In this paper we start with an exact projective sequence of finite hypergroups and use successive substitution to construct a new surjective projective system of finite hypergroups whose limit is almost discrete. We prove that all compact almost discrete hypergroups appear in this way—up to isomorphism and up to a technical restriction. We also determine the duals of these hypergroups, and we present some examples coming from partitions of compact totally disconnected groups.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1997

References

1. Bloom, W. and Heyer, H., The Fourier transformation of probability measures on hypergroups, Rend. Mat. 2(1982), 315334.Google Scholar
2. Bloom, W. and Heyer, H., Harmonic Analysis of Probability Measures on Hypergroups, De Gruyter 1995.Google Scholar
3. Connettand, W.C. Schwartz, A.L., Product formulas, hypergroups and the Jacobipolynomials, Bull. Amer. Math. Soc. 22(1990), 9196.Google Scholar
4. Dunkl, C.F., The measure algebra of a locally compact hypergroup, Trans. Amer. Math. Soc. 179(1973), 331348.Google Scholar
5. Dunkl, C.F. and Ramirez, D.E., A family of countable compact P*-hypergroups, Trans. Amer. Math. Soc. 202(1975), 339356.Google Scholar
6. Fournier, J.J.F. and Ross, K.A., Random Fourier series on compact Abelian hypergroups, J. Austral. Math. Soc. Ser. A 37(1984), 4581.Google Scholar
7. Hewitt, E. and Ross, K.A., Abstract Harmonic Analysis I, II. Berlin, Heidelberg, New York, Springer, 1979. 1970.Google Scholar
8. Jewett, R.I., Spaces with an abstract convolution of measures, Adv. in Math. 18(1975), 1—101.Google Scholar
9. Michael, E., Topologies on spaces of subsets, Trans. Amer. Math. Soc. 71(1951), 152182.Google Scholar
10. Ross, K.A., Hypergroups and centers of measure algebras, Symposia Math. 22(1977), 189203.Google Scholar
11. Schwartz, A.L., Classification of one-dimensional hypergroups, Proc. Amer. Math. Soc. 103(1988), 10731081.Google Scholar
12. Spector, R., Sur la structure locale des groupes abéliens localement compacts, Bull. Soc. Math. France 24(1970).Google Scholar
13. Spector, R., Une classe d'hypergroupes dénombrables, C. R. Acad. Sci. Paris A 281(1975), 105106.Google Scholar
1. Spector, R., Mesures invariantes sur les hypergroupes, Trans. Amer. Math. Soc. 239(1978), 147166.Google Scholar
15. Voit, M., Factorization of probability measures on symmetric hypergroups, J. Austral. Math. Soc. Ser. A 50(1991), 417467.Google Scholar
16. Voit, M., Duals of subhypergroups and quotients of commutative hypergroups, Math. Z. 210(1992), 289304.Google Scholar
17. Voit, M., A generalization of orbital morphisms of hypergroups. In: Probability Measures on Groups X, Proc. Conf., Oberwolfach, 1990. 425433. Plenum Press, 1992.Google Scholar
1. Voit, M., Projective and inductive limits of hypergroups, Proc. London Math. Soc. 67(1993), 617648.Google Scholar
1. Voit, M., Substitution of open subhypergroups, Hokkaido Math. J. 23(1994), 143183.Google Scholar
20. Vrem, R., Harmonic analysis on compact hypergroups, Pacific J. Math. 85(1979), 239251.Google Scholar
21. Vrem, R., Hypergroup joins and their dual objects, Pacific J. Math. 111(1984), 483495.Google Scholar
2. Vrem, R., Connectivity and supernormality results for hypergroups, Math. Z. 195(1987), 419428.Google Scholar
23. Zeuner, Hm., One-dimensional hypergroups, Adv. in Math. 76(1989), 1—18.Google Scholar
24. Zeuner, Hm., Duality of commutative hypergroups. In: Probability Measures on Groups X,Proc. Conf., Oberwolfach, 1990. 467488. Plenum Press, 1992.Google Scholar