London Algebra Colloquium abstract

Irreducible maximal subgroups of classical algebraic groups

Professor Donna Testerman (EPFL), 7th March 2013


We consider triples (H, G, V), where G is a simple algebraic group defined over an algebraically closed field k, with closed positive-dimensional subgroup H, and V is a kG-module on which H acts irreducibly. All such triples where H is connected were determined by Dynkin (in the case of zero characteristic) and by Seitz and Testerman (in positive characteristic). The triples where G is exceptional and H is disconnected were determined by Ghandour. Certain configurations with G classical and H disconnected were studied by Ford. We will discuss our work on the case where G is classical and H is disconnected and maximal among closed subgroups of G.