Lethbridge Number Theory and Combinatorics Seminar: Joy Morris

  • Date: 02/06/2017
  • Time: 12:00
Joy Morris, University of Lethbridge

University of British Columbia


Oriented Regular Representations


An oriented graph is a digraph with at most one arc between any pair of vertices.
We say that the action of a group on a set of points is regular if it is sharply transitive; that is, there is exactly one group element mapping any point to any other point. An oriented regular representation (ORR) for a group G is an oriented graph whose automorphism group is isomorphic to the regular action of G on the vertices. In 1980, Babai asked which groups admit an ORR. I will discuss this problem, and present joint work with Pablo Spiga in which we showed that every non-solvable group admits an ORR.

Other Information: 

Location: B660 University Hall
Web page: http://www.cs.uleth.ca/~nathanng/ntcoseminar/