15:00
Random elements in finite groups
Abstract
How to uniformly, or at least almost uniformly, choose an element from a finite group ? When G is too large to enumerate all its elements, direct (pseudo)random selection is impossible. However, if we have an explicit set of generators of G (e.g., as in the Rubik's cube group), several methods are available. This talk will focus on one such method based on the well-known product replacement algorithm. I will discuss how recent results on property (T) by Kaluba, Kielak, Nowak and Ozawa partially explain the surprisingly good performance of this algorithm.
Consensus-Based Bi-Level Optimization
We all have to live with uncertainty. We attribute good and bad events as ‘due to chance’, label people as ‘lucky’, and (sometimes) admit our ignorance. In this Oxford Mathematics Public Lecture David shows how to use the theory of probability to take apart all these ideas, and demonstrate how you can put numbers on your ignorance, and then measure how good those numbers are.