SEMINAR: Groups and Combinatorics Seminar, Finite 2-set-homogeneous graphs

Jin-Xin Zhou (Beijing Jiaotong University)

will speak on

Finite 2-set-homogeneous graphs

at 3pm Friday 19 September in Weatherburn Lecture Theatre.

Abstract:

Let k be a positive integer. A finite graph G is said to be k-set-homogeneous if for any two isomorphic subgraphs, A and B, of G, each of order at most k, there is an automorphism of G taking A to B. Clearly, every k-set-homogeneous graph is also 2-set-homogeneous for k >= 2. We study the 2-set-homogeneous graphs. It is shown that a 2-set-homogeneous graph G either belongs to some known families of graphs or Aut(G) is an almost simple primitive rank 4 permutation group with exactly one orbital self-paired.