Past Events

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...

In 1959, Farahat and Higman showed a remarkable property about the symmetric group: the structure constants for the center of the group algebra Sn depend polynomially on n and that there exists an infinite-dimensional algebra, which we call the...

It is conjectured that there is no projective plane of order 12. Balanced splittable Hadamard matrices were introduced in 2018. In 2023, it was shown that a projective plane of order 12 is equivalent to a balanced multi-splittable Hadamard matrix of...