University of Bristol
Time: 16:00-18:00 (GMT+8), Saturday March 4th, 2023
Abstract: In this talk we will discuss two ways of breaking all the non-trivial symmetries of a graph: pointwise and setwise, which involve base sizes and distinguishing numbers of permutation groups, respectively. These two invariants have been investigated for many decades, finding a wide range of applications. I will report on my recent progress on determining base sizes of some primitive groups, with some connections to other interesting problems. In particular, I will give the first family of primitive groups arising in the O'Nan-Scott theorem for which the exact base size has been computed in all cases.
Host: 谢贻林 Yilin Xie