On Bounding the Number of Automorphisms of a Tournament

Series
Graph Theory Working Seminar
Time
Wednesday, February 20, 2019 - 4:30pm for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Michael Wigal – Georgia Tech
Organizer
Xingxing Yu
Let $g(n) = \max_{|T| = n}|\text{Aut}(T)|$ where $T$ is a tournament. Goldberg and Moon conjectured that $g(n) \le \sqrt{3}^{n-1}$ for all $n \ge 1$ with equality holding if and only if $n$ is a power of 3. Dixon proved the conjecture using the Feit-Thompson theorem. Alspach later gave a purely combinatorial proof. We discuss Alspach's proof and and some of its applications.