Counting cycles in graphs: A rank-1 version of the Hanna Neumann Conjecture
Thursday, 1 October, 2015 - 16:30 to 17:30
A "W-cycle" in a labelled digraph Γ is a closed path whose label is the word W. I will describe a simple result about bounding the number of W-cycles in a deterministically labelled connected digraph.
The result appears to be very simple but we do not know of an elementary proof. Perhaps someone from the audience will have some ideas.
This is joint work with Joseph Helfer, and has been proven independently by Lars Louder and Henry Wilton.