14.00-14.45 Christophe Pittet (Genève), The exact convergence rate in the ergodic theorem of Lubotzky Phillips Sarnak.15.00-15.45 Thiebout Delabie (Orsay), High dimensional cuts and coarse embedding.16.15-17.00 Alina Vdovina (Newcastle), Ramanujan cubical complexes as higher-dimensional expanders.
Inspired by the model theoretic study of profinite groups, we discuss the foundations of a model theoretic approach to proalgebraic groups. Our axiomatization is based on the tannakian philosophy. Through a tensor analog of skeletal categories we are able to consider neutral tannakian categories with a fibre functor as many-sorted first order structures. The theory of a diagonalizable proalgebraic group is well understood. It is determined by the theory of the base field and the theory of its character group. This is joint work with Anand Pillay.
