Canal-U

Mon compte

Résultats de recherche

Nombre de programmes trouvés : 750
Conférences

le (1h4m1s)

Feng Luo - Discrete conformal geometry of polyhedral surfaces and its convergence

Our recent joint work with D. Gu established a discrete version of the uniformization theorem for compact polyhedral surfaces.   In this talk, we prove that discrete uniformizaton maps converge to conformal maps when the triangulations are sufficiently fine chosen.  We will also discuss the relationship between the discrete uniformization theorem and convex polyhedral surfaces  in the hyperbolic 3-space.  This is a joint work with J. Sun and T. Wu.
Voir la vidéo
Conférences

le (58m50s)

Stéphane Saboureau - Sweep-outs, width estimates and volume

Sweep-out techniques in geometry and topology have recently received a great deal of attention, leading to major breakthroughs. In this talk, we will present several width estimates relying on min-max arguments in relation to the volume of Riemannian manifolds. Dealing with the case of surfaces first, we will focus our attention on generalisations in higher dimension and present new estimates obtained in a work in progress.
Voir la vidéo
Conférences

le (1h3m4s)

Jean-Marc Schlenker - Anti-de Sitter geometry and polyhedra inscribed in quadrics

Anti-de Sitter geometry is a Lorentzian analog of hyperbolic geometry. In the last 25 years a number of connections have emerged between 3-dimensional anti-de Sitter geometry and the geometry of hyperbolic sufaces. We will explain how the study of ideal polyhedra in anti-de Sitter space leads to an answer to a question of Steiner (1832) on the combinatorics of polyhedra that can be inscribed in a quadric. Joint work with Jeff Danciger and Sara Maloni.
Voir la vidéo
Conférences

le (52m51s)

Burkhard Wilking - Manifolds with almost nonnegative curvature operator

We show that n-manifolds with a lower volume bound v and upper diameter bound D whose curvature operator is bounded below by $-\varepsilon(n,v,D)$ also admit metrics with nonnegative curvature operator. The proof relies on heat kernel estimates for the Ricci flow and shows that various smoothing properties of the Ricci flow remain valid if an upper curvature bound is replaced by a lower volume bound. nonnegative curvature operator.
Voir la vidéo
Conférences

le (1h37s)

Juan Souto - Counting curves on surfaces

An old theorem of Huber asserts that the number of closed geodesics of length at most L on a hyperbolic surface is asymptotic to $\frac{e^L}L$. However, things are less clear if one either fixes the type of the curve, possibly changing the notion of length, or if one counts types of curves. Here, two curves are of the same type if they differ by a mapping class. I will describe some results in these directions.
Voir la vidéo
Conférences

le (45m38s)

Genevieve Walsh - Boundaries of Kleinian groups

We study the problem of classifying Kleinian groups via the topology of their limit sets. In particular, we are interested in one-ended convex-cocompact Kleinian groups where each piece in the JSJ decomposition is a free group, and we describe interesting examples in this situation.  In certain cases we show that the type of Kleinian group is determined by the topology of its group boundary.  We conjecture that this is not the case in general.  We also determine the homeomorphism types of planar boundaries that can occur.  This is joint work in progress with Peter Haissinsky and Luisa Paoluzzi.
Voir la vidéo
Conférences

le (56m16s)

Reto Buzano - Minimal hypersurfaces with bounded index and bounded area

We study sequences of closed minimal hypersurfaces (in closed Riemannian manifolds) that have uniformly bounded index and area. In particular, we develop a bubbling result which yields a bound on the total curvature along the sequence. As a consequence, we obtain qualitative control on the topology of minimal hypersurfaces in terms of index and area. This is joint work with Ben Sharp.
Voir la vidéo

 
FMSH
 
Facebook Twitter Google+
Mon Compte