1-cohomologie des représentations unitaires des groupes de Lie semi-simples et résolubles. Produits tensoriels continus de représentations
A descriptive view of unitary group representations
In this paper, we will study the relative complexity of the unitary duals of countable groups. In particular, we will explain that if and are countable amenable non-type I groups, then the unitary duals of and are Borel isomorphic.
A new duality theory for compact groups.
A non-seperable measureable choice principle related to induced representations.
A property for locally convex *-algebras related to property (T) and character amenability
For a locally convex *-algebra A equipped with a fixed continuous *-character ε (which is roughly speaking a generalized F*-algebra), we define a cohomological property, called property (FH), which is similar to character amenability. Let be the space of continuous functions with compact support on a second countable locally compact group G equipped with the convolution *-algebra structure and a certain inductive topology. We show that has property (FH) if and only if G has property (T). On...
A Stone-Weierstrass theorem for group representations.
A survey on representations of the unitary group U(∞)
Algèbre de Jordan et ensemble de Wallach.
Almost L2 matrix coefficients.
Amenable unitary representations of locally compact groups.
An analytic series of irreducible representations of the free group
Let be a free group on generators. We construct the series of uniformly bounded representations of acting on the common Hilbert space, depending analytically on the complex parameter z, , such that each representation is irreducible. If is real or then is unitary; in other cases cannot be made unitary. For representations and are congruent modulo compact operators.
An example of a generalized completely continuous representation of a locally compact group
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”.
An -criterion of amenability for a locally compact group.
Analyse harmonique hyperbolique : représentations et contractions des groupes
Analyse Harmonique sur les groupes de Heisenberg généralisés.
Averages of unitary representations and weak mixing of random walks
Let S be a locally compact (σ-compact) group or semigroup, and let T(t) be a continuous representation of S by contractions in a Banach space X. For a regular probability μ on S, we study the convergence of the powers of the μ-average Ux = ʃ T(t)xdμ(t). Our main results for random walks on a group G are: (i) The following are equivalent for an adapted regular probability on G: μ is strictly aperiodic; converges weakly for every continuous unitary representation of G; U is weakly mixing for any...
Bitwisted Burnside-Frobenius theorem and Dehn conjugacy problem
It is proved for Abelian groups that the Reidemeister coincidence number of two endomorphisms ϕ and ψ is equal to the number of coincidence points of ϕ̂ and ψ̂ on the unitary dual, if the Reidemeister number is finite. An affirmative answer to the bitwisted Dehn conjugacy problem for almost polycyclic groups is obtained. Finally, we explain why the Reidemeister numbers are always infinite for injective endomorphisms of Baumslag-Solitar groups.
Characterizations of seminorms given by continuous linear functionals on normed linear spaces and applications to Gel'fand measures.
Characterizing moore groups by Tensor products of irreducible representations.
Chu-Dualität und zwei Klassen maximal fastperiodischer Gruppen.