2019 May 07

# Anatoly Vershik (St. Petersburg) Соmbinatorial (locally finite) еncoding of the Bernoulli processes with infinite entropy.

2:00pm to 3:00pm

Abstract. The realization of m.p automorphisms as transfer on the space of the paths on the graded graphs allows to use new kind of encoding of one-sided Bernoulli shift. I will start with simple example how to realize Bernoulli shift in the locally finite space (graph) $\prod_n {1,2,\dots n}$ (triangle compact.) Much more complicated example connected to old papers by S.Kerov-Vershik and recent by Romik-Sniady in which one-sided Bernoulli shift is realized as Schutzenberger transfer on the space of infinite Young tableaux with Plancherel Measure. These examples open series of
2019 Jun 27

# Group and dynamics seminar: Michael Chapman (HUJI): Cutoff on Ramanujan complexes

10:00am to 11:15am

Ross 70
2019 Jun 20

# Groups & dynamics seminar: Noam Kolodner (HUJI) - Surjectivity of morphisms of labeled core-graph under the action of automorphisms of a free group

10:00am to 11:00am

For a finitely generated subgroup H of the free group F_r, the Stallings graph of H is a finite combinatorial graph, whose edges are labeled by r letters (and their inverses), so that paths in the graphs correspond precisely to the words in H. Furthermore, there is a map between the graphs of two subgroups H and J, precisely when one is a subgroups of the other. Stallings theory studies the algebraic information which is encoded in the combinatorics of these graphs and maps.
2019 Jun 06

# Groups and dynamics seminar - Yoav Gat (Technion) - Counting lattice points on the Heisenberg groups - A generalization of a classical problem to a non-commutative setting

10:00am to 11:00am

Abstract: In this talk, I shall present a generalization of the lattice point counting problem for Euclidean balls in the context of a certain type of homogeneous groups, the so-called Heisenberg groups.