London Algebra Colloquium abstract

Is Babai afraid of spiders?

Nick Gill (Open University), 17th March 2011

Abstract

I describe some interesting permutation group results that emerged from a recent attempt to prove Babai’s conjecture for the alternating groups. The work is joint with Helfgott, and with a number of people from the University of Western Australia.

Specifically we study “mixing elements” in the natural action of An on the set {1, . . . ,n}, and on k-tuples of distinct elements from {1, . . . ,n}. We use “spider diagrams” to construct words of decreasing support; these ideas lead to some interesting general questions . . .