Orateur: Caterina Campagnolo
Titre: Right angled hyperbolic polytopes do not exist in dimension greater than 4.
Résumé: In this talk we will prove the result obtained by E. Vinberg in the '80s: if n>4, there exists no compact right angled polytope in the hyperbolic n-space. The proof is mostly combinatorial, except for one crucial property of hyperbolic geometry.
This fact is of interest in geometric group theory, since nicely presentable groups arise as groups generated by reflections across the faces of certain polytopes.

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