Real projective structures on Riemann surfaces
Recent developments in the theory of function spaces
Rechtsdistributive Multiplikationen auf homogenen Räumen.
Rectifiability and parameterization of intrinsic regular surfaces in the Heisenberg group
We construct an intrinsic regular surface in the first Heisenberg group equipped wiht its Carnot-Carathéodory metric which has euclidean Hausdorff dimension . Moreover we prove that each intrinsic regular surface in this setting is a -dimensional topological manifold admitting a -Hölder continuous parameterization.
Rectifiability and perimeter in step 2 Groups
We study finite perimeter sets in step 2 Carnot groups. In this way we extend the classical De Giorgi’s theory, developed in Euclidean spaces by De Giorgi, as well as its generalization, considered by the authors, in Heisenberg groups. A structure theorem for sets of finite perimeter and consequently a divergence theorem are obtained. Full proofs of these results, comments and an exhaustive bibliography can be found in our preprint (2001).
Rectifiability and perimeter in step 2 groups
Rectification : «Algèbres de Clifford symplectiques et revêtements spinoriels du groupe symplectique»
Reducibility of certain representations for symplectic and odd-orthogonal groups
Reducibility of generalized principal series representations of via base change
Reducibility of Unramified Unitary Principal Series Representations of p-Adic Groups and Class-1 Representations.
Reduction of Hamiltonian Systems, Affine Lie Algebras and Lax Equations.
Reduction of invariant differential operators and expansions of conical distributions for
Regular behavior at infinity of stationary measures of stochastic recursion on NA groups
Let N be a simply connected nilpotent Lie group and let be a semidirect product, acting on N by diagonal automorphisms. Let (Qₙ,Mₙ) be a sequence of i.i.d. random variables with values in S. Under natural conditions, including contractivity in the mean, there is a unique stationary measure ν on N for the Markov process Xₙ = MₙXn-1 + Qₙ. We prove that for an appropriate homogeneous norm on N there is χ₀ such that . In particular, this applies to classical Poisson kernels on symmetric spaces,...
Regular infinite dimensional Lie groups.
Regular Lie groups and a theorem of Lie-Palais.
Regular orbital measures on Lie algebras
Let H₀ be a regular element of an irreducible Lie algebra , and let be the orbital measure supported on . We show that if and only if k > dim /(dim - rank ).
Regular trace formula and base change for
The “regular”trace formula, for a test function with a local component which is Iwahori-biinvariant and sufficiently regular with respect to the other components, is developed in the context of a reductive group. It is used to give a simple proof of the theory of base-change for cuspidal automorphic representations of which have a supercuspidal component. A purely local proof is given to transfer orbital integrals of sufficiently many spherical functions, by relating them to regular Iwahori functions....
*-Regularity of Exponential Lie Groups.
Regularity of minimizers of the calculus of variations in Carnot groups via hypoellipticity of systems of Hörmander type
We prove the hypoellipticity for systems of Hörmander type with constant coefficients in Carnot groups of step 2. This result is used to implement blow-up methods and prove partial regularity for local minimizers of non-convex functionals, and for solutions of non-linear systems which appear in the study of non-isotropic metric structures with scalings. We also establish estimates of the Hausdorff dimension of the singular set.
Regularly related lattices in locally compact groups.