Cross Sections and an Explicit Formula for the Plancherel Measure on a Nilpotent Lie Group.
Darstellungen von Liegruppen und Approximationsprozesse auf Banachräumen.
Dirichlet problem with L-boundary data in contractible domains of Carnot groups
Let be a sub-laplacian on a stratified Lie group . In this paper we study the Dirichlet problem for with -boundary data, on domains which are contractible with respect to the natural dilations of . One of the main difficulties we face is the presence of non-regular boundary points for the usual Dirichlet problem for . A potential theory approach is followed. The main results are applied to study a suitable notion of Hardy spaces.
Discrete spectrum of the reductive dual pair (O(p,q), Sp(2m)).
Distributions coniques sur le cône des matrices de rang un et de trace nulle
Eigenfunction expansions of functions describing systems with symmetries.
Eigenvalues of the Hodge Laplacian on the Heisenberg group.
Elliptic diffusions on infinite products.
Endoscopic groups and packets of non-tempered representations
Équations différentielles invariantes sur les groupes et algèbres de Lie réductifs
Soient un groupe de Lie réductif d’algèbre de Lie , un opérateur différentiel non nul à coefficients constants et -invariant sur , et une distribution -invariante sur . Nous montrons que l’équation différentielle a des solutions dans l’espace des distributions -invariantes sur ; de plus, si est tempérée ou d’ordre fini, on peut trouver des solutions ayant les mêmes propriétés. Si est un opérateur différentiel bi-invariant non nul sur , Benabdallah et Rouvière ont donné une condition...
Equivalence of weak and viscosity solutions to the -Laplace equation in the Heisenberg group.
Equivariant Imbeddings of Compact Abelian Lie Groups of Transformations.
Espaces de Poisson des groupes de Lie
Espaces de Poisson des groupes localement compacts
Estimates from Below for Lebesgue Constants of Fourier Series on Compact Lie Groups.
États cohérents, théorie spectrale et représentations de groupes nilpotents
Explicit fundamental solutions of some second order differential operators on Heisenberg groups
Let p,q,n be natural numbers such that p+q = n. Let be either ℂ, the complex numbers field, or ℍ, the quaternionic division algebra. We consider the Heisenberg group N(p,q,) defined ⁿ × ℑ , with group law given by (v,ζ)(v’,ζ’) = (v + v’, ζ + ζ’- 1/2 ℑ B(v,v’)), where . Let U(p,q,) be the group of n × n matrices with coefficients in that leave the form B invariant. We compute explicit fundamental solutions of some second order differential operators on N(p,q,) which are canonically associated to...
Fonctions harmoniques positives sur certains groupes de Lie résolubles connexes
Fourier transform of Schwartz functions on the Heisenberg group
Let H₁ be the 3-dimensional Heisenberg group. We prove that a modified version of the spherical transform is an isomorphism between the space 𝓢ₘ(H₁) of Schwartz functions of type m and the space 𝓢(Σₘ) consisting of restrictions of Schwartz functions on ℝ² to a subset Σₘ of the Heisenberg fan with |m| of the half-lines removed. This result is then applied to study the case of general Schwartz functions on H₁.
Fourier-Wigner transforms and Liouville's theorems for the sub-Laplacian on the Heisenberg group
The sub-Laplacian on the Heisenberg group is first decomposed into twisted Laplacians parametrized by Planck's constant. Using Fourier-Wigner transforms so parametrized, we prove that the twisted Laplacians are globally hypoelliptic in the setting of tempered distributions. This result on global hypoellipticity is then used to obtain Liouville's theorems for harmonic functions for the sub-Laplacian on the Heisenberg group.