Bifunctors and cohomological finite generation

by Prof. Wilberd van der Kallen (Utrecht University, Netherlands)

Thursday 13 Jun 2013, 14:30 → 15:30 Asia/Kolkata

AG-77 (Colaba Campus)

The category of strict polynomial bifunctors over the field $\Bbb F_p$ has an interesting homological algebra. There are surprising formulas that describe the effect of Frobenius twist on certain Ext groups. We will explain some of this. The bifunctor theory has been crucial in the proof of my cohomological finite generation conjecture: If a reductive algebraic group $G$ defined over a field $k$ acts algebraically via algebra automorphisms on a finite type commutative $k$-algebra, then the graded $k$-algebra $H^*(G,A)$ is finitely generated.