This is the homepage of the University of Illinois Urbana-Champaign Algebraic Geometry Seminar, organized by Deniz Genlik and Sheldon Katz. We meet Tuesdays at 3-3:50pm at Transportation Building 204.
Other algebraic geometry activities at Illinois: AG lunch (Tu 12:30-1:30pm, Harker Hall 201), AG preprint seminar (Tu 2-2:50pm, Transportation Building 204). For more information, join our mailing list, either by visiting here or emailing Felix Janda, or Sheldon Katz.
Spring 2026 Schedule:
Feb 17: Ruoxi Li (University of Illinois Urbana-Champaign)
Title: Towards derived Log GLSM: log cosections
Abstract: In Log Gauged Linear Sigma Models (log GLSM), two types of reduced perfect obstruction theories play crucial roles in computation of higher genus Gromov-Witten invariants. In this talk, I will present derived geometric constructions of these reduced perfect obstruction theories using log cosections, an approach which eliminates certain technical conditions required in the classical setting. I will also provide local models to illustrate this approach. If time permitting, I will sketch the construction of the derived moduli stack for a prototype of derived Log GLSM. This is joint work with Felix Janda.
Feb 24: Philip Engel (University of Illinois Chicago)
Title: Matroids and the integral Hodge conjecture for abelian varieties
Abstract: We will discuss a proof that the integral Hodge conjecture is false for a very general abelian variety of dimension ≥ 4. Associated to any regular matroid is a degeneration of principally polarized abelian varieties. We introduce a new combinatorial invariant of regular matroids, which obstructs the algebraicity of the minimal curve class, on the very general fiber of the associated degeneration. In concert with a result of Voisin, one deduces (via the intermediate Jacobian) the stable irrationality of a very general cubic threefold. This is joint work with Olivier de Gaay Fortman and Stefan Schreieder.
March 3: Leo Herr (Virginia Tech)
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March 10: Tondeur Lectures by June Huh (Princeton University)
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March 24: Rob Silversmith (Emory University)
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March 31: Ajith Urundolil Kumaran (Massachusetts Institute of Technology)
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April 7: David Jensen (University of Kentucky)
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April 14: Matt Larson (Princeton University)
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April 21: Grace Chen (University of Illinois Urbana-Champaign)
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April 28: Siddarth Kannan (Massachusetts Institute of Technology)M
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May 5: Colin Ingalls (Carleton University)
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