[16/10/2023] Kostas Karagiannis (University of Manchester), Polynomial invariants of finite group schemes I

Dear all,

We are happy to inform you that GANT is back!!!! We would like to let you know that for this semester the structure of the seminar is different than the previous years. We will have a series of 2-3 talks on a specific topic by an expert.

For the first series of talks the speaker is Kostas Karagiannis (University of Manchester) and the first talk is given on Monday 16 October 2023,  2-3 pm (Time in Greece, GMT+3). The title and abstract of the topic are the following:

Title: Polynomial invariants of finite group schemes

Abstract: It was previously shown by Peter Symonds that when a finite group acts on a polynomial ring over a field of prime characteristic, then only finitely many isomorphism classes of indecomposable -modules occur as summands of , and that the Castelnuovo-Mumford regularity of the invariant subring is at most zero.

The main purpose of this series of talks will be to present joint work with Peter Symonds that generalizes the above results when one replaces the acting object by a finite group scheme. Considerable effort will be put into introducing the audience to the concepts and tools necessary to make sense of the problems and present the arguments of the relevant proofs. On the side of the acting object, this includes a crash course on finite group schemes over fields and their representations; on the side of the object acted upon the focus will be on the complex and local cohomology. In any case, every effort will be made to restrict the prerequisites to basic familiarity with representation theory of finite groups, affine algebraic geometry and homological methods in commutative algebra.

Zoom link: https://authgr.zoom.us/j/2586769419?pwd=dElhRGxrRlh0V003emc3ejRjSVZrUT09
Meeting ID: 258 676 9419
Passcode: 908335

ATTENTION: The time of the talks is 2-3pm instead of 4-5pm as it was.