Centre for Mathematics, University of Coimbra

Seminars

Closure of Riemannian foliations

2025-06-25

Speaker: Mateus Moreira de Melo (Univ. Fed. Espírito Santo, Brazil)

The Molino-Alexandrino-Radeschi Theorem establishes the smoothness of the leaf closure of a Riemannian foliation, that is, the partition of a manifold obtained by taking the closures of the leaves of a Riemannian foliation is itself a Riemannian foliation. In this talk, I will present this...

Classifying cubic graphs avoiding spectral gap sets

2025-06-25

Speaker: Gordon Royle (Univ. Western Australia, Australia)

Spectral graph theory is the study of the relationship between the graphical properties of a graph and the spectral properties (i.e., eigenvalues and eigenvectors) of various matrices associated with that graph, most commonly the adjacency matrix. The spectrum of the...

Drazin inverses in (dagger) categories

2025-08-19

Speaker: Jean-Simon Pacaud Lemay (Macquarie Univ., Sydney, Australia)

Drazin inverses are a special kind of generalized inverse that have been extensively studied and have many applications in ring theory, semigroup theory, and matrix theory. Drazin inverses can also be defined for endomorphisms in any category. A natural question is whether one can extend the...

A general approach to pointfree \(T_0\) spaces

2025-08-19

Speaker: Anna Laura Suarez (Univ. Western Cape, South Africa)

The classical dual adjunction between frames and spaces, given by the functors \( O\colon \mathbf{Top}\to\mathbf{Frm} \) and \( \mathsf{pt}\colon\mathbf{Frm}\to\mathbf{Top} \), restricts to a dual equivalence between sober spaces and spatial frames. Another pointfree approach to the study of...

Large random tilings of a hexagon

2025-09-15

Speaker: Arno Kuijlaars (KU Leuven, Belgium)

TBA...

Quasi-orthogonal polynomials and positive quadrature on the unit circle

2025-09-18

Speaker: Ruymán Cruz Barroso (University of La Laguna, Spain)

TBA...