# Institut Mittag-Leffler workshop

Posted on 2016-06-01

In May 2016, I attended a week-long workshop on Branching Problems for Reductive Groups at the Institut Mittag-Leffler (Djursholm, Sweden).

I gave a lecture on An overview of representations of reductive algebraic groups; essentially everything I discussed can be found in the text of Jens Jantzen on the representation theory of algebraic groups. I tried to focus on things that seem to me to be relevant to the difficulties presented by modular representation theory to “branching problems”:

• (Hochschild) cohomology,
• the description of simple representations for reductive groups,
• reduction mod p and
• the Jantzen filtration of Weyl modules Δ(λ).

Here are the slides from my talk.