Lectures on algebraic stacks

Tuesday, 3 Oct.  11.30 am

====================

Venue: Ramanujan Hall

Host: Sudarshan Gurjar

Speaker: Nitin Nitsure

Affiliation: TIFR, Mumbai (retd)

Title: Algebraic stacks

Topology and Related Topics Seminar

Tuesday, 3  October  2023, 2:30 pm

=========================

Venue: Room 215

Host: Rekha Santhanam

Speaker: Bittu Singh

Affiliation: IIT Bombay

Title: Quillen stratification theorem

Abstract:  In our previous sessions, we have successfully constructed the universal bundle and demonstrated the equivalence between two definitions of group cohomology from both algebraic and topological perspectives. In this talk, I will present the proof of a theorem, which asserts that if the total space of a principal G-bundle is aspherical, it is indeed the universal bundle. Additionally, I will introduce another approach to constructing the universal G-bundle using simplicial sets, an approach attributed to Milnor.