Workshop on Recent Developments in Hodge Theory and O-minimality

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.

Date & Time

March 09, 2026 | 2:30pm – 3:30pm
Add to calendar 03/09/2026 14:30 03/09/2026 15:30 Workshop on Recent Developments in Hodge Theory and O-minimality use-title Topic: Matroids and the Integral Hodge Conjecture for Abelian Varieties Speakers: Philip Engel, University of Illinois More: https://www.ias.edu/events/workshop-recent-developments-hodge-theory-and-o-minimality-1 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. Simonyi Hall 101 a7a99c3d46944b65a08073518d638c23

Location

Simonyi Hall 101

Speakers

Philip Engel, University of Illinois

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