5 papers
Th{é}orie de l'homotopie quantitative
Pierre Pansu
The aim of homotopy theory in topology is to simplify, after continuous deformation, continuous maps between topological spaces. What prevents this from happening are homotopy inva…
Cohomologie en degré 1 des espaces homogènes
Pierre Pansu
The -cohomology in degree 1 of Riemannian homogeneous spaces is computed. It turns out that reduced cohomology does not vanish exactly for spaces quasiisometric to negatively…
Plongements quasiisométriques du groupe de Heisenberg dans , d'après Cheeger, Kleiner, Lee, Naor
Pierre Pansu
This is a short survey of Cheeger and Kleiner's nonembeddability theorem for Heisenberg group into .
Cohomologie et pincement
Pierre Pansu
A sharp vanishing theorem for the cohomology torsion of Riemannian manifolds with pinched negative curvature is given. It follows that certain negatively curved homogeneous s…
Pincement du plan hyperbolique complexe
Pierre Pansu
-cohomology of rank one symmetric spaces of noncompact type is shown to be Hausdorff for values of where this does not follow from curvature pinching. Using the multiplica…