Past Events

The formalization of string diagrams, in a 1991 paper by Andre Joyal and Ross Street, was a seminal event. They defined a basic diagrammatic language and proved its validity for rigorous mathematics in any monoidal category, and in doing so they laid...

The even filtration, introduced by Hahn-Raksit-Wilson, is a canonical filtration attached to a commutative ring spectrum which measures its failure to be even. Despite its simple definition, the even filtration recovers many arithmetically important...

Combinatorial Algebra meets Algebraic Combinatorics (CAAC) is a series of workshops that bring together researchers in algebraic combinatorics, combinatorial aspects of commutative algebra, geometry, and representation theory, and computational...

In this seminar we recall the spectral partitioning method based on a Fiedler vector, i.e., an eigenvector corresponding to the second smallest eigenvalue of the Laplacian matrix of a graph. This problem corresponds to the minimization of a quadratic...

The derivation of effective macroscopic theories approximating microscopic systems of interacting particles is a major question in non-equilibrium statistical mechanics. For non-interacting particles this is a relatively easy task. However when...

In this talk, we study the singularities of secant varieties of smooth projective varieties when the embedding line bundle is sufficiently positive. We give a necessary and sufficient condition for these to have p-Du Bois singularities. In addition...

Classical algorithms are defined on inputs of different sizes. In contrast, data-driven algorithms, that is, algorithms learned from some data, may only be defined on inputs of the same size as the data. What does it mean for an algorithm to be...

Let s(n) denote the sum of proper divisors of a positive integer n. In 1992, Erd\H{o}s, Granville, Pomerance, and Spiro conjectured that if  is a set of integers with asymptotic density zero then the preimage set s−1() also has asymptotic density...

We consider metric tensors on undirected weighted graphs G, which allows us to treat P(G), the set of probability vectors on G, as a length space. On defines a divergence operator div_\mu(G) for mu in P(G), in such a way that we can use control...

Suppose a graph G has list chromatic number k. It is easy to see that if L is a (k+1)-list assignment for G, then G admits two L-colourings f and g where f(v) =/= g(v) for every vertex v in the graph. But what if we want still more disjoint L...