Geodesically complete Lorentzian metrics on some homogeneous 3 manifolds.
Geodesically equivalent metrics on homogenous spaces
Two metrics on a manifold are geodesically equivalent if the sets of their unparameterized geodesics coincide. We show that if two -invariant metrics of arbitrary signature on homogenous space are geodesically equivalent, they are affinely equivalent, i.e. they have the same Levi-Civita connection. We also prove that the existence of nonproportional, geodesically equivalent, -invariant metrics on homogenous space implies that their holonomy algebra cannot be full. We give an algorithm for...
Geometria integral de los grupos ST(n+1) y ST 1 (n+1) en el sepacio proyectivo Pn
Geometric construction of the classical r-matrix for the elliptic Calogero-Moser system
By applying the Hamiltonian reduction technique we derive a matrix first order differential equation that yields the classical r-matrices of the elliptic (Euler-) Calogero-Moser systems as well as their degenerations.
Geometric invariant theory on Stein spaces.
Geometric Modules over the Burnside Ring.
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 Quantization and Multiplicities of Group Representations.
Geometric realization of discrete series for semisimple symmetric spaces.
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...
Geometric theta-lifting for the dual pair
Let be a smooth projective curve over an algebraically closed field of characteristic . Consider the dual pair over with split. Write and for the stacks of -torsors and -torsors on . The theta-kernel on yields theta-lifting functors and between the corresponding derived categories. We describe the relation of these functors with Hecke operators. In two particular cases these functors realize the geometric Langlands functoriality for the above pair (in the non ramified case)....
Geometrically finite groups, Patterson-Sullivan measures and Ratner's rigidity theorem.
Géométrie de la structure adjointe sur un groupe de Lie et algèbres de type
À partir de l’étude de l’intégrabilité de la structure adjointe sur un groupe de Lie , on est amené à introduire l’algèbre de Lie des opérateurs symétriques du crochet de l’algèbre de Lie de . On fait apparaître une décomposition canonique de toute algèbre de Lie de centre nul en somme directe d’idéaux caractéristiques, où est somme de deux sous-algèbres abéliennes et où est formée d’opérateurs nilpotents.Nous montrons que l’étude de la platitude à l’ordre 2 de la structure adjointe...
Géométrie et analyse sur les arbres
Géométries modèles de dimension trois
On expose une preuve détaillée de la classification par Thurston des huit géométries modèles de dimension trois.
Geometry of -step nilpotent groups with a left invariant metric
Geometry of biinvariant subsets of complex semisimple Lie groups
Geometry of compactifications of locally symmetric spaces
For a locally symmetric space , we define a compactification which we call the “geodesic compactification”. It is constructed by adding limit points in to certain geodesics in . The geodesic compactification arises in other contexts. Two general constructions of Gromov for an ideal boundary of a Riemannian manifold give for locally symmetric spaces. Moreover, has a natural group theoretic construction using the Tits building. The geodesic compactification plays two fundamental roles in...
Geometry of Poisson structures.
Girsanov type formula for a Lie group valued brownian motion