Displaying 41 – 60 of 264

Showing per page

Large-scale isoperimetry on locally compact groups and applications

Romain Tessera (2006/2007)

Séminaire de théorie spectrale et géométrie

We introduce various notions of large-scale isoperimetric profile on a locally compact, compactly generated amenable group. These asymptotic quantities provide measurements of the degree of amenability of the group. We are particularly interested in a class of groups with exponential volume growth which are the most amenable possible in that sense. We show that these groups share various interesting properties such as the speed of on-diagonal decay of random walks, the vanishing of the reduced first...

Le complexe de Koszul en algèbre et topologie

Stephen Halperin (1987)

Annales de l'institut Fourier

The Koszul complex, as introduced in 1950, was a differential graded algebra which modelled a principal fibre bundle. Since then it has been an effective tool, both in algebra and in topology, for the calculation of homological and homotopical invariants. After a partial summary of these results we recall more recent generalizations of this complex, and some applications.

Le spectre des longueurs des surfaces hyperboliques : un exemple de rigidité.

Emmanuel Philippe (2009/2010)

Séminaire de théorie spectrale et géométrie

Après avoir présenté quelques résultats récents portant sur l’étude du spectre des longueurs des surfaces hyperboliques avec ou sans singularités, on démontre que les sphères possédant trois points coniques sont, dans leur classe, spectralement rigides.

Currently displaying 41 – 60 of 264