Diskrete Untergruppen von SL2 (IR).
Divergent trajectories of flows on homogeneous spaces and Diophantine approximation.
Effective equidistribution of S-integral points on symmetric varieties
Let be a global field of characteristic not 2. Let be a symmetric variety defined over and a finite set of places of . We obtain counting and equidistribution results for the S-integral points of . Our results are effective when is a number field.
Ergodic decomposition for pairs of lattices in Lie groups.
Erratum: A Geometric Construction of the Discrete Series for Semisimple Lie Groups.
Erratum: J. Eur. Math. Soc. 1, 199-235 (1999)
Existence of compact quotients of homogeneous spaces, measurably proper actions, and decay of matrix coefficients
Finite groups of rotations. A supplement to the preceding article.
Finitely generated fuchsian groups.
Finiteness theorems for discrete subgroups of bounded covolume in semi-simple groups
Finitude géométrique en géométrie de Hilbert
On étudie la notion de finitude géométrique pour certaines géométries de Hilbert définies par un ouvert strictement convexe à bord de classe .La définition dans le cadre des espaces Gromov-hyperboliques fait intervenir l’action du groupe discret considéré sur le bord de l’espace. On montre, en construisant explicitement un contre-exemple, que cette définition doit être renforcée pour obtenir des définitions équivalentes en termes de la géométrie de l’orbifold quotient, similaires à celles obtenues...
Flexibility of surface groups in classical simple Lie groups
We show that a surface group of high genus contained in a classical simple Lie group can be deformed to become Zariski dense, unless the Lie group is (resp. , odd) and the surface group is maximal in some (resp. ). This is a converse, for classical groups, to a rigidity result of S. Bradlow, O. García-Prada and P. Gothen.
Formal degree and existence of stable arithmetic lattices of cuspidal representations of p-adic reductive groups.
Formules de Matsushima, de Garland et propriété (T) pour des groupes agissant sur des espaces symétriques ou des immeubles
Gamma-cohomology and the Selberg zeta function.
Generalized Picard lattices arising from half-integral conditions
Geodesic cycles and the Weil representation I ; quotients of hyperbolic space and Siegel modular forms
Geometric orbifolds.
An orbifold is a topological space which ?locally looks like? the orbit space of a properly discontinuous group action on a manifold. After a brief review of basic concepts, we consider the special case 3-dimensional orbifolds of the form GammaM, where M is a simply-connected 3-dimensional homogeneous space corresponding to one of Thurston?s eight geometries, and where Gamma < Isom(M) acts properly discontinuously. A general description of these geometric orbifolds is given and the closed...
Geometric structures on the complement of a projective arrangement
Consider a complex projective space with its Fubini-Study metric. We study certain one parameter deformations of this metric on the complement of an arrangement (= finite union of hyperplanes) whose Levi-Civita connection is of Dunkl type. Interesting examples are obtained from the arrangements defined by finite complex reflection groups. We determine a parameter interval for which the metric is locally of Fubini-Study type, flat, or complex-hyperbolic. We find a finite subset of this interval for...
Geometrically finite groups, Patterson-Sullivan measures and Ratner's rigidity theorem.