Stretch factors of graph maps and polynomial invariants of free-by-cyclic groups

by Dr Radhika Gupta (TIFR, Mumbai)

Thursday 20 Oct 2022, 16:00 → 17:00 Asia/Kolkata

AG-69

Abstract: In this talk we will associate two numbers, the geometric and homological stretch factors, to a graph map and see under what conditions they are equal. We will then upgrade these notions to free group automorphisms. Finally, we will cast these numbers in terms of two polynomial invariants, the Alexander polynomial and McMullen polynomial, associated to a free-by-cyclic group and see how these polynomials are related to each other. ------------------------------------------------- YouTube live link: https://youtu.be/DJQy9fZ8lro --------------------------------------------------