Idempotents in complex group rings: Theorems of Zalesskij and Bass revisited.
Multiplicité de petites valeurs propres du laplacien
Grandes valeurs propres du laplacien et graphes
Small eigenvalues of Riemann surfaces and graphs.
Analyse Harmonique sur les groupes de Heisenberg généralisés.
Spèctre du Laplacian, graphes et topologie de Fell.
Lattices in product of trees
Groups acting on trees : from local to global structure
Réseaux arithmétiques et commensurateur d'après G. A. Margulis.
Bounded Kähler class rigidity of actions on hermitian symmetric spaces
Erratum: J. Eur. Math. Soc. 1, 199-235 (1999)
Bounded cohomology of lattices in higher rank Lie groups
We prove that the natural map from bounded to usual cohomology is injective if is an irreducible cocompact lattice in a higher rank Lie group. This result holds also for nontrivial unitary coefficients, and implies finiteness results for : the stable commutator length vanishes and any –action on the circle is almost trivial. We introduce the continuous bounded cohomology of a locally compact group and prove our statements by relating to the continuous bounded cohomology of the ambient group...
A lower bound on ... for geometrically finite hyperbolic n-manifolds.
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