Geometric Representation Theory

Event Information Cohomology of the moduli of Higgs bundles, the Hausel-Thaddeus conjecture, and the P=W conjecture
14:00 on Friday September 25, 2020
15:30 on Friday September 25, 2020
Virtual
Junliang Shen

MIT

We describe the cohomological structure of the moduli space of stable SL_n Higgs bundles on a curve following the topological mirror symmetry conjecture of Hausel-Thaddeus. For the approach, we establish a connection between:

(a) the moduli space of twisted Higgs bundles by an effective divisor of degree greater than 2g-2, and

(b) the moduli space of K_C-Higgs bundles,

using vanishing cycle functors. This allows us to apply Ngô's support theorem, which has a simpler form in the case (a) (by Ngô, Chaudouard-Laumon, de Cataldo), to the case (b) which concerns hyper-Kähler geometries. In particular, this gives a new proof of the Hausel-Thaddeus conjecture proven previously by Groechenig-Wyss-Ziegler via p-adic integration. We will also discuss connections to the P=W conjecture if time permits. Based on joint work with Davesh Maulik.

The seminar will be held over Zoom. Register in advance for this meeting using the following link: https://utoronto.zoom.us/meeting/register/tJ0kdOGuqDsuH9PfX5Zb-yslzxAXuLL9HwDN After registering, you will receive a confirmation email containing information about joining the meeting.