# London Algebra Colloquium abstract

## Irreducible maximal subgroups of classical algebraic groups

### Professor Donna Testerman (EPFL), 7th March 2013

#### Abstract

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*.