Foliation dynamics and leaf invariants.
An explicit family of Folner sets is constructed for some directed groups acting on a rooted tree of sublogarithmic valency by alternate permutations. In the case of bounded valency, these groups were known to be amenable by probabilistic methods. The present construction provides a new and independent proof of amenability, using neither random walks, nor word length.
Soit un réel de . Nous étudions le système d’équations de convolution suivantNous démontrons que les exponentielles polynômes solutions de sont denses dans l’espace des solutions du système d’équations; l’idéal de engendré par les transformées de Fourier des deux mesures intervenant ici est “slowly decreasing” au sens de Berenstein-Taylor. Lorsque n’est pas un nombre de Liouville, nous montrons qu’il existe un ouvert relativement compact telle que toute solution distribution de régulière...
A Gutzmer formula for the complexification of a Riemann symmetric space. We consider a complex manifold and a real Lie group of holomorphic automorphisms of . The question we study is, for a holomorphic function on , to evaluate the integral of over a -orbit by using the harmonic analysis of . When is an annulus in the complex plane and the rotation group, it is solved by a classical formula which is sometimes called Gutzmer’s formula. We establish a generalization of it when is...
This work deals with various questions concerning Fourier multipliers on , Schur multipliers on the Schatten class as well as their completely bounded versions when and are viewed as operator spaces. For this purpose we use subsets of ℤ enjoying the non-commutative Λ(p)-property which is a new analytic property much stronger than the classical Λ(p)-property. We start by studying the notion of non-commutative Λ(p)-sets in the general case of an arbitrary discrete group before turning to the...