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Nombre de programmes trouvés : 757

le (51m50s)

Melanie Rupflin - Horizontal curves of metrics and applications to geometric flows

On closed surfaces there are three basic ways to evolve a metric, by conformal change, by pull-back with diffeomorphisms and by horizontal curves, moving orthogonally to the first two types of evolution. As we will discuss in this talk, horizontal curves are very well behaved even if the underlying conformal structures degenerate in moduli space as t to T. We can describe where the metrics will have essentially settled down to the limit by time t T as opposed to regions on which the metric still has to do an infinite amount of stretching. This quantified information is essential in ...
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le (51m42s)

S. Donaldson - Boundary value problems for $G_2$ structures

In the lecture we consider the existence of G2 structures on 7-manifolds with boundary, with prescribed data on the boundary. In the first part we will review general background and theory, including Hitchin’s variational approach. We will then discuss in more detail reductions of the problem in the presence of symmetry and in ”adiabatic limits”, and connections with real and complex Monge-Ampère equations.
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le (50m52s)

D. Brotbek - On the hyperbolicity of general hypersurfaces

A smooth projective variety over the complex numbers is said to be (Brody) hyperbolic if it doesn’t contain any entire curve. Kobayashi conjectured in the 70’s that general hypersurfaces of sufficiently large degree in PN are hyperbolic. This conjecture was only recently proved by Siu. The purpose of this talk is to present a new proof of this conjecture. The main idea of the proof, based on the theory of jet differential equations, is to establish that a stronger property, open in the Zariski topology, ...
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le (50m47s)

Strict monotonicity of percolation thresholds under covering maps (workshop ERC Nemo Processus ponctuels et graphes aléatoires unimodulaires)

Percolation is a model for propagation in porous media that as introduced in  1957 by Broadbent and Hammersley. An infinite graph G models the geometry of the situation and a parameter p embodies its porosity: percolation consists in keeping independently each edge with probability p, erasing it otherwise, and looking at the infinite connected components of the resulting graph. It turns out that there is a critical porosity: for smaller porosities, all components are finite almost surely, while for larger ones, there is almost surely at ...
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