Spring 2026
- Week 2 (April 6): Justin Bloom
- Title: Character theory for reductive groups
- Abstract: What are reductive groups? Why are they important?
What's so great about their representation theory? And WHAT are tilting modules? All these questions, and more, will be answered
in our first StARTS meeting of Spring 2026. Good vibes only!
- Week 3 (April 13): Wolfgang Allred
- Title: Koszul Duality for Rep Theorists
- Abstract: Have you heard the words "Koszul duality" and looked them up online,
only to be met with a bewildering variety of examples and phrases like "Lie operad" or "cobar construction"?
If so, you're not alone and help is available.
I will go over some of the basic notions to do with Koszul duality in representation theory,
and, if there is time, talk about some of the larger picture ideas in the more general homological phenomena of Koszul duality.
- Week 4 (April 20): Alex Waugh
- Title: Ghosts hiding in the Frobenius
- Abstract: In characteristic p, we often have the freshman's dream:
(x+y)^p = x^p + y^p. In commutative algebra, this is an absolute equality.
That is, the equality sign means equality on the nose. In this talk, I will discuss a derived/homotopical perspective on this dream,
where equality is replaced with "homotopic". By keeping track of all of the resulting homotopical data,
I will show how to produce maps which were hidden within the derived Frobenius and produce operations
which will act on Hopf algebra cohomology. Time permitting, I will connect this construction with the vanishing
of certain Tate cohomology and operad theory.
- Week 5 (April 27): Andrew Aguilar
- Title: How Exactly Does One Derive a Category?
- Abstract: Many important functors over abelian categories are, unfortunately, not exact.
To resolve this, we introduce a “universal” functor obtained from the original which “completes” the complexes.
But the correct place to study these new derived functors is the derived category.
That is, the category where quasi-isomorphisms are actually isomorphisms.
In this talk we wish to extend this construction to more general exact categories, where the notion of a quasi-isomorphism, in the usual sense, is impossible!
- Week 6 (May 4): Bryan Lu
- Title: 0-Hecke Algebra Reps in the Tableau Menagerie
- Abstract: Ever since Krob and Thibon ('96) have developed quasisymmetric and non-commutative characters for 0-Hecke algebra representations,
in subsequent studies of the combinatorial Hopf algebras QSym and NSym, one can try to construct the 0-Hecke representations corresponding to various elements.
This is especially nice from a combinatorial perspective, since unlike in standard treatments of symmetric group representation theory,
0-Hecke algebra representations admit a nice combinatorial description via Young diagrams and Young tableaux.
We will survey this connection and play around with various kinds of tableaux (potentially in short exact sequences) to get a sense of how these representations behave.
- Week 7 (May 11): Ting Gong
- Week 8 (May 18): Justin Bloom
- Title: Lectures on Dieudonné theory Part I
- Abstract: TBA
- Week 9 (May 25): Justin Bloom
- Title: Lectures on Dieudonné theory Part II
- Abstract: TBA
- Week 10 (June 1): Justin Bloom
- Title: Lectures on Dieudonné theory Part III
- Abstract: TBA