Special Year 2025-2026: Arithmetic Geometry, Hodge Theory, and O-minimality

Special Year Research Seminar

December 04, 2025 | 1:00pm - 2:00pm

Many geometric spaces carry natural collections of special submanifolds that encode their internal symmetries. Examples include abelian varieties and their sub-abelian varieties, locally symmetric spaces with their totally geodesic subspaces, period...

Special Year Learning Seminar

December 03, 2025 | 2:00pm - 3:00pm

Ben Bakker explained to us how to construct moduli spaces of polarized Hodge structures, and then produced period maps associated to families of smooth projective varieties. However, in practice one often encounters a family of smooth varieties...

Special Year Research Seminar

November 20, 2025 | 1:00pm - 2:00pm

The goal of these lectures is to present the fundamentals of Simpson’s correspondence, generalizing classical Hodge theory, between complex local systems and semistable Higgs bundles with vanishing Chern classes on smooth projective varieties.

Special Year Learning Seminar

November 19, 2025 | 2:00pm - 3:00pm

The goal of these lectures is to present the fundamentals of Simpson’s correspondence, generalizing classical Hodge theory, between complex local systems and semistable Higgs bundles with vanishing Chern classes on smooth projective varieties.

Special Year Research Seminar

November 14, 2025 | 1:00pm - 2:00pm

Speaker #1 (Tran): On a projective variety, Simpson showed that there is a homeomorphism between the moduli space of semisimple flat bundles and that of polystable Higgs bundles with vanishing Chern classes. Recently, Bakker, Brunebarbe and...

Special Year Research Seminar

November 13, 2025 | 1:00pm - 2:00pm

We give a lower bound on the codimension of a component of the non-abelian Hodge locus within a leaf of the isomonodromy foliation on the relative de Rham moduli space of flat vector bundles on an algebraic curve. The bound follows from a more...

Special Year Learning Seminar

November 12, 2025 | 2:00pm - 3:00pm

A Hodge structure is a certain linear algebraic datum.  Importantly, the cohomology groups of any smooth projective algebraic variety come equipped with Hodge structures which encode the integrals of algebraic differential forms over topological...

Special Year Learning Seminar

November 05, 2025 | 2:00pm - 3:00pm

Differential Galois groups are algebraic groups that describe symmetries of some systems of differential equations. The solutions considered can live in any differential field and thus a natural framework to consider such symmetries is the setting...

Special Year Research Seminar

October 30, 2025 | 1:00pm - 2:00pm

In this talk, I will discuss some effective computations for variations of integral Hodge structures.

Several years ago, with Ren and Javanpeykar-Kühne, I conjectured (in the Shimura setting) that a variation has only finitely many "non-factor"...

Special Year Learning Seminar

October 29, 2025 | 2:00pm - 3:00pm

A Hodge structure is a certain linear algebraic datum.  Importantly, the cohomology groups of any smooth projective algebraic variety come equipped with Hodge structures which encode the integrals of algebraic differential forms over topological...