Goal

The goal of this seminar was to study recent work of Landesman-Litt on local systems of geometric origin over general curves. The main results are contained in LL22b and LL22c. We focused on the case of unipotent monodromy at the cusps to avoid the machinery of parabolic and coparabolic structures; a simplified version of the first paper is available as LL22a. The program is available as a PDF.

Schedule

Date Speaker Topic Notes
November 9RajuIntroduction to local systems of geometric originNotes
November 14RajuFinish introductionNotes
November 30JoshAtiyah bundles and isomonodromic deformationsNotes
December 7ScottThe non-GGG lemma
December 14YichenProve Theorem 1.3.4 of LL22a; state Theorem 1.2.4 of LL22aNotes
January 9BrunoBackground on CPVHS and positivity; prove Theorems 1.2.8, 1.2.4, and 1.2.6 of LL22aNotes
January 11RajuIntroduction to MCG, MCG-finite representations, and the main theorem of LL22cNotes
January 18, 25VasilyCohomology rank bound for a unitary local system on a versal family of curvesNotes
February 8/15TBACohomological rigidity for canonical representations and the main theorem for unitary local systems
February 15/22TBAThe main theorem for semisimple local systems and arithmetic applications
TBATBAApplications to the Putman-Wieland conjecture

References