Date/Time: 4 March 2022, 4:30pm EST
 Location: West Chester University, Anderson Hall 211 and on Zoom
  Speaker: Rylee Lyman (Rutgers-Newark) 
    Title: Train track maps on graphs of groups and CTs for free products

 Abstract: A homotopy equivalence of a graph is a train track map
when it sends vertices to vertices and the restriction of any iterate of
the map to an edge yields an immersion. (Relative) train track maps were
introduced by Bestvina and Handel in 1992; since then they have become
one of the main tools in the study of outer automorphisms of free
groups. More recently in 2011, Feighn and Handel introduced a stronger
kind of relative train track map called a CT and proved their existence
for all outer automorphisms of free groups after passing to a power. We
extend the theory of relative train track maps to certain graphs of
groups and the theory of CTs to free products (that is, graphs of groups
with trivial edge groups).