we will welcome Yassine Guerch who is finishing his thesis (Geometry and rigidity of relative automorphism groups) in Paris-Saclay.
So February 11th at 11am at the FRUMAM.
Here is Yassine’s title and summary:
Title: Relative Flows and Growth in Out(F_n)
Abstract: Be $n$ an integer and $Out(F_n)$ the group of external automorphisms of a nonabelian free group. Or $[g]$ a conjugation class of $F_n$ and $F in Out(F_n)$. The $[g]$ class is exponentially growing if the length (for a fixed base of $F_n$) of $F m([g])$ grows exponentially with $m. We build a compact topological space, called a space of relative currents, on which $F$ agît by homeomorphism and which allows to translate exponential growth into dynamic terms. We will give algebraic applications of these dynamic results, which impose constraints on the structure of subgroups of $Out(F_n)$.