5 may 2022 -- 12:00
Aula Tricerri, DIMaI, Firenze
Seminario di Geometria del Dipartimento di Matematica e Informatica "Ulisse Dini" dell'Università di Firenze
Abstract.
I'll discuss a global geometric version of a theorem of Lusztig on the divisibility by the Steinberg module. I will then use this result to argue that, in the setting of the geometric Langlands conjecture, the phenomenon of divergence at infinity on the stack of G-bundles on a smooth complete curve is controlled by the locus of semisimple local systems (for the Langlands dual group). This can be explained by means of the Deligne-Lusztig functors (substitutes for the Serre functors, which do not make sense in our situation). Time permitting, I will explain how to reinterpret the above situation using opers.