The tangent bundle of -velocities over a homogeneous space
The 𝔳-radial Paley-Wiener theorem for the Helgason Fourier transform on Damek-Ricci spaces
We prove the Paley-Wiener theorem for the Helgason Fourier transform of smooth compactly supported 𝔳-radial functions on a Damek-Ricci space S = NA.
Three-dimensional complex homogeneous complex contact manifolds.
Three-dimensional curvature homogeneous hypersurfaces
This paper is motivated by the open problem whether a three-dimensional curvature homogeneous hypersurface of a real space form is locally homogeneous or not. We give some partial positive answers.
Three-dimensional slant submanifolds of -contact manifolds.
Topologie du feuilletage fortement stable
Soient une variété de Hadamard de courbure et un groupe d’isométries non élémentaire. Nous montrons qu’il y a équivalence entre la non-arithméticité du spectre des longueurs de , le mélange topologique du flot géodésique et l’existence d’une feuille dense pour le feuilletage fortement stable.
Transitive conformal holonomy groups
For (M, [g]) a conformal manifold of signature (p, q) and dimension at least three, the conformal holonomy group Hol(M, [g]) ⊂ O(p + 1, q + 1) is an invariant induced by the canonical Cartan geometry of (M, [g]). We give a description of all possible connected conformal holonomy groups which act transitively on the Möbius sphere S p,q, the homogeneous model space for conformal structures of signature (p, q). The main part of this description is a list of all such groups which also act irreducibly...
Translation of natural operators on manifolds with AHS-structures.
Translation of natural operators on manifolds with AHS-structures
We introduce an explicit procedure to generate natural operators on manifolds with almost Hermitian symmetric structures and work out several examples of this procedure in the case of almost Grassmannian structures.
Translation surfaces of finite type in
In the homogeneous space Sol, a translation surface is parametrized by , where and are curves contained in coordinate planes. In this article, we study translation invariant surfaces in , which has finite type immersion.
Transport de mesure et courbures de Ricci synthétiques dans le groupe de Heisenberg
Dans ces notes il sera expliqué que la propriété est vérifiée par le groupe de Heisenberg muni de la distance de Carnot-Carathéodory et de la mesure de Lebesgue. Cette propriété correspond pour les espaces métriques mesurés à une courbure de Ricci positive. Comme application, les mesures interpolées par transport de mesure sont absolument continues. En revanche, la courbure-dimension , une autre courbure de Ricci synthétique adaptée aux espaces métriques mesurés est fausse pour .
Transversally symmetric immersions
We introduce the notions of (extrinsic) locally transversally symmetric immersions and submanifolds in a Riemannian manifold equipped with a unit Killing vector field as analogues of those of (extrinsic) locally symmetric immersions and submanifolds. We treat their geometric properties, derive several characterizations and give a list of examples.
Twistor spaces for Riemannian symmetric spaces.
Two-dimensional Helmholtz spaces.