Algèbre et géométrie

January 31 (wednesday)   14.00 - 14.45 Valérie Berthé (Paris VII),  "Dendric subshifts  and groups" 15.00 - 15.45  Nguyen-Bac Dang, (Orsay) , "Variation of the Hausdorff dimension of limits set and degenerating Schottky groups" 16.15 - 17.00  Bruno Duchesne (Orsay), TBA   Valérie Berthé,   "Dendric subshifts  and groups"   We discuss a family of  symbolic dynamical systems  that have remarkable  group properties, the family of dendric words. This family  includes numerous classical families of   symbolic dynamical systems,   among others codings of interval exchanges. Their return words  form […]

March 12 (Tuesday) This seminar meeting will focus on interactions between groups and random walks, and will be dedicated to our beloved mentor and colleague, Anatoly Moiseevich Vershik, who pioneered this field.   14.00 - 14.45 Cyril Houdayer (ENS Paris)  ``The noncommutative factor theorem for lattices in product groups''. 15.00 - 15.45   Kunal Chawla (Princeton)   "The Poisson boundary of hyperbolic groups without moment conditions". 16.15 - 17.00   Sara Brofferio (Université Paris-Est Créteil Val-de-Marne),  "Uniqueness of  invariant measures for random homeomorphisms of the real line". ----   Cyril Houdayer  […]

April 16 (Tuesday) For this seminar we will have the pleasure of listening to three talks: 14.00 - 14.45 Andrei Jaikin-Zapirain (UAM), "Compressed subgroups in free groups are inert" 15.00 - 15.45 Timothée Marquis (UCL), "Amalgams of rational unipotent groups and residual nilpotence". 16.15 - 17.00 Olga Kharlampovich (CUNY), "Quantification of separability of cubically convex-cocompact subgroups of RAAGs via representations".  Andrei Jaikin-Zapirain  "Compressed subgroups in free groups are inert".   Let F be a free group. A finitely generated subgroup H is called compressed in F if it is not contained […]

An afternoon on random walks on groups. 14.00 - 14.45   Giulio Tiozzo (Toronto) ``Roots of Alexander polynomials of random positive braids'';   15.00 - 15.45   Amaury Freslon (Orsay)  ``How to (badly) shuffle cards?''; 16.15 - 17.00   Charles Bordenave (Marseille) ``Strong convergence of matrix algebras and applications to random walks''.   Giulio Tiozzo  ``Roots of Alexander polynomials of random positive braids'' As originally observed experimentally by Dehornoy, roots of Alexander polynomials of random knots display interesting patterns. In this work, joint with N. Dunfield, we prove several results […]