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Spectral subspaces for the Fourier algebra

K. Parthasarathy, R. Prakash (2007)

Colloquium Mathematicae

In this note we define and explore, à la Godement, spectral subspaces of Banach space representations of the Fourier-Eymard algebra of a (nonabelian) locally compact group.

Spectrum of commutative Banach algebras and isomorphism of C*-algebras related to locally compact groups

Zhiguo Hu (1998)

Studia Mathematica

Let A be a semisimple commutative regular tauberian Banach algebra with spectrum Σ A . In this paper, we study the norm spectra of elements of s p a n ¯ Σ A and present some applications. In particular, we characterize the discreteness of Σ A in terms of norm spectra. The algebra A is said to have property (S) if, for all φ ¯ Σ A 0 , φ has a nonempty norm spectrum. For a locally compact group G, let 2 d ( Ĝ ) denote the C*-algebra generated by left translation operators on L 2 ( G ) and G d denote the discrete group G. We prove that the Fourier...

Spherical functions and uniformly bounded representations of free groups

Tadeusz Pytlik (1991)

Studia Mathematica

We give a construction of an analytic series of uniformly bounded representations of a free group G, through the action of G on its Poisson boundary. These representations are irreducible and give as their coefficients all the spherical functions on G which tend to zero at infinity. The principal and the complementary series of unitary representations are included. We also prove that this construction and the other known constructions lead to equivalent representations.

Stabilité du comportement des marches aléatoires sur un groupe localement compact

Driss Gretete (2008)

Annales de l'I.H.P. Probabilités et statistiques

Dans cet article nous démontrons un théorème de stabilité des probabilités de retour sur un groupe localement compact unimodulaire, séparable et compactement engendré. Nous démontrons que le comportement asymptotique de F*(2n)(e) ne dépend pas de la densité F sous des hypothèses naturelles. A titre d’exemple nous établissons que la probabilité de retour sur une large classe de groupes résolubles se comporte comme exp(−n1/3).

Stable rank and real rank of compact transformation group C*-algebras

Robert J. Archbold, Eberhard Kaniuth (2006)

Studia Mathematica

Let (G,X) be a transformation group, where X is a locally compact Hausdorff space and G is a compact group. We investigate the stable rank and the real rank of the transformation group C*-algebra C₀(X)⋊ G. Explicit formulae are given in the case where X and G are second countable and X is locally of finite G-orbit type. As a consequence, we calculate the ranks of the group C*-algebra C*(ℝⁿ ⋊ G), where G is a connected closed subgroup of SO(n) acting on ℝⁿ by rotation.

Structure de certaines C * -algèbres associées aux réseaux de PSL 2 ( )

François Pierrot (2002)

Annales de l’institut Fourier

En utilisant la structure infinitésimale des représentations unitaires irréductibles de PSL 2 ( ) , nous donnons une description complète de certaines C * - algèbres associées aux réseaux de PSL 2 ( ) , répondant ainsi à certaines questions de Bekka–de La Harpe–Valette.

Subgroups of -factorizable groups

Constancio Hernández, Mihail G. Tkachenko (1998)

Commentationes Mathematicae Universitatis Carolinae

The properties of -factorizable groups and their subgroups are studied. We show that a locally compact group G is -factorizable if and only if G is σ -compact. It is proved that a subgroup H of an -factorizable group G is -factorizable if and only if H is z -embedded in G . Therefore, a subgroup of an -factorizable group need not be -factorizable, and we present a method for constructing non- -factorizable dense subgroups of a special class of -factorizable groups. Finally, we construct a closed...

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