Neeraj Deshmukh (University of Georgia): A motivic Riemann-Roch theorem for Deligne-Mumford stacks
Feb 10, 2026 11:00 am
Transportation Building 204
- Sponsor
- UIUC Math Department
- Views
- 105
- Originating Calendar
- Mathematics Seminar Series: Topology
- The Grothendieck-Riemann-Roch theorem fails to hold in the case of Deligne-Mumford stacks due to the presence of stabilisers. Several modified constructions, using the inertia stack and related objects, have been proposed by Edidin, Graham, Toën, and others.
In this talk, we will analyse Toën's formulation of the Riemann-Roch theorem from a motivic perspective. More specifically, we will construct an object (associated to every Deligne-Mumford stack) in Voevodsky's triangulated category of motives which we will then use to reformulate (and perhaps even generalise) Toën's Riemann-Roch isomorphism in the language of motivic cohomology. This is joint work with Utsav Choudhury and Amit Hogadi.