Events and Activities

We will discuss combinatorial and algebraic aspects of regular Hessenberg varieties, a large class of subvarieties of the flag variety G/B. For the special case of Peterson varieties, we show their equivariant structure constants are non-negative...

There is a bijection between solutions of the Kadomtsev-Petiashvili (KP) hierarchy and points on an infinite Grassmannian, now often simply referred to as "the Sato Grassmannian". This connection is made via the Plücker coordinates, the expansion...

Expansion is an important notion in graphs, and comes in several equivalent formulations, including (1) convergence of random walks, (2) having no small cuts, and (3) having a large spectral gap. I will talk about a higher dimensional generalization...

Given a triple (X,π,s) consisting of a homogeneous space X=G/P, a dominant weight π giving a projective embedding of X, and a reduced expression s for the minimal coset representative of w_0 in the parabolic quotient W/W_P, we construct a polytope...

I will give an overview of the classical study of local complex dynamics in one dimension, and the more recent study in several complex variables; with an emphasis on the `neutral’ case, that is when the local behavior is neither attracting nor...

In recent work with Hajir, Larsen and Maire, we have proved that a large class of finitely generated pro-p groups G can be realized as tamely ramified extensions of a number field K, though ramification at an infinite number of primes is required...

Persistence modules and their associated barcodes were intensively studied since the early 2000s with a view towards applied mathematics. Recently they have also found numerous applications in pure mathematics. We will discuss a few examples from...

High dimensional expansion comes in two flavors: spectral, which relates to random walks;  and cosystolic, which relates to chains of linear maps. The later is a more mysterious notion, which turns out related to a variety of applications such as...