Structure of Blaschke cocycles
Structure of function algebras on foliated manifolds.
Structure of the kernel of higher spin Dirac operators
Polynomials on with values in an irreducible -module form a natural representation space for the group . These representations are completely reducible. In the paper, we give a complete description of their decompositions into irreducible components for polynomials with values in a certain range of irreducible modules. The results are used to describe the structure of kernels of conformally invariant elliptic first order systems acting on maps on with values in these modules.
Subalgebra of associated with Laplacian on a Lie group
Subalgebras generated by extreme points in Fourier-Stieltjes algebras of locally compact groups
Let G be a locally compact group, G* be the set of all extreme points of the set of normalized continuous positive definite functions of G, and a(G) be the closed subalgebra generated by G* in B(G). When G is abelian, G* is the set of Dirac measures of the dual group Ĝ, and a(G) can be identified as l¹(Ĝ). We study the properties of a(G), particularly its spectrum and its dual von Neumann algebra.
Sub-Laplacian with drift in nilpotent Lie groups
We consider the heat kernel corresponding to the left invariant sub-Laplacian with drift term in the first commutator of the Lie algebra, on a nilpotent Lie group. We improve the results obtained by G. Alexopoulos in [1], [2] proving the “exact Gaussian factor” exp(-|g|²/4(1+ε)t) in the large time upper Gaussian estimate for . We also obtain a large time lower Gaussian estimate for .
Sub-Laplacians of holomorphic -type on exponential Lie groups
In this survey article, I shall give an overview on some recent developments concerning the -functional calculus for sub-Laplacians on exponential solvable Lie groups. In particular, I shall give an outline on some recent joint work with W. Hebisch and J. Ludwig on sub-Laplacians which are of holomorphic -type, in the sense that every -spectral multiplier for will be holomorphic in some domain.
Subspaces of with unique topological left invariant mean
Sugli insiemi piccoli in un gruppo
Un insieme in un gruppo si dice piccolo se esistono infiniti traslati di a due a due disgiunti. In questa nota dimostriamo in modo elementare che, sotto opportune ipotesi, non può essere l'unione di un numero finito di insiemi piccoli (e una generalizzazione di questo risultato).
Suites algébriques, automates et substitutions
Suites de -orbite finie.
Suites définies négatives et espaces de Dirichlet sur la sphère
Suites équiréparties et ensembles mesurables au sens de Riemann
Suites uniformément distribuées et fonctions faiblement presque-périodiques
Summability and integrability of Vilenkin series.
Summable families in nuclear groups
Nuclear groups form a class of abelian topological groups which contains LCA groups and nuclear locally convex spaces, and is closed with respect to certain natural operations. In nuclear locally convex spaces, weakly summable families are strongly summable, and strongly summable are absolutely summable. It is shown that these theorems can be generalized in a natural way to nuclear groups.
Superstability of functional equations related to spherical functions
In this paper we prove stability-type theorems for functional equations related to spherical functions. Our proofs are based on superstability-type methods and on the method of invariant means.
Supports of Gauss measures on semisimple Lie groups.
Sur certaines propriétés des représentations unitaires des groups localement compacts
Sur certains éléments ergodiques dans