Special Year 2024-25: Algebraic and Geometric Combinatorics

Geometry of Matroid Workshop

October 23, 2024 | 10:30am - 11:30am

Abstract: I will introduce the external activity complex of an ordered pair of matroids on the same ground set. This is the combinatorial analogue of the Schubert variety of an ordered pair of linear subspaces of a fixed space, which is also new...

Geometry of Matroid Workshop

October 23, 2024 | 9:00am - 10:00am

Abstract: The groundbreaking results by Huh (further extended in joint work with Adiprasito and Katz) allowed to associate to a matroid a class in the Chow ring of the permutohedral variety. The technique turned out to be especially powerful, as...

Geometry of Matroid Workshop

October 22, 2024 | 2:30pm - 3:30pm

Abstract: We study the tropicalization of principal minors of positive definite matrices over a real valued field. This tropicalization forms a subset of M-concave functions on the discrete n-dimensional cube. We show that it coincides with a linear...

Geometry of Matroid Workshop

October 22, 2024 | 12:00pm - 1:00pm

Abstract: We characterize the topology of the space of Lorentzian polynomials with a given support in terms of the local Dressian. We prove that this space can be compactified to a closed Euclidean ball whose dimension is the rank of the Tutte group...

Geometry of Matroid Workshop

October 22, 2024 | 10:00am - 11:00am

Abstract: This talk asks which tropicalisations of subvarieties of the torus know the cohomology of the original variety. A motivating example are linear embeddings of complements of hyperplane arrangements. 

We can prove that the tropicalisation...

Geometry of Matroid Workshop

October 21, 2024 | 2:30pm - 3:30pm

Abstract: The foundation of a matroid is an algebraic invariant that controls representations over any partial field, hyperfield, or more generally, any pasture. We show that, under certain conditions, the foundation of a generalized parallel...

Geometry of Matroid Workshop

October 21, 2024 | 12:00pm - 1:00pm

Abstract: After a gentle introduction to matroids, I will present parts of a new OSCAR software module for matroids through several examples. I will focus on computing the moduli space of a matroid which is the space of all arrangements of...

Geometry of Matroid Workshop

October 21, 2024 | 10:00am - 11:00am

Abstract: A toric vector bundle is a torus equivariant vector bundle on a toric variety.

We begin by recalling the classification of toric vector bundles due to Klyachko. The Klyachko data of a toric vector bundle can be interpreted as a "piecewise...

Geometry of Matroid Workshop

October 21, 2024 | 10:00am - October 25, 2024 | 12:15pm

 

Sponsored by Dr. John P. Hempel 

Organizers: Matt Baker, Chris Eur, June Huh, Oliver Lorscheid, and Felipe Rincon

This event brought together leading researchers in different areas of combinatorial geometry. This workshop was a part of the special...

Amplitudes and Combinatorics Synergy Event

October 03, 2024 | 10:00am - 5:00pm
October 04, 2024 | 10:00am - 5:00pm

Summary: This event aims to foster collaboration between combinatorialists and amplitudologists in two ways: first by bridging language and concept barriers, and second by highlighting open problems of mutual interest. 

Schedule:  Available here

Conta...