Centre for Mathematics, University of Coimbra

Seminars

On the commuting tensor product of symmetric multicategories and their bimodules

2026-01-13

Speaker: Nicola Gambino (University of Manchester, UK )

We provide a unified treatment of several commuting tensor products considered in the literature, including the tensor product of enriched categories and the Boardman-Vogt tensor product of symmetric multicategories, subsuming work of Elmendorf and Mandell. We then show how a commuting...

Ehresmann connections in a tangent category

2026-01-13

Speaker: Geoffrey Cruttwell (Mount Allison University, Canada)

Tangent categories, first defined by Jiří Rosický in 1984, are a categorical structure which allows one to abstractly work with and reason about many of the ideas in differential geometry. In this talk, I'll discuss how to define and work with Ehresmann connections in a tangent...

Geodesic completeness problems on Lie groups: metric, algebraic, and dynamical viewpoints

2026-01-14

Speaker: Salah Chaib (CMAT, Univ. Minho)

In this talk, I will discuss the geodesic completeness problem for left-invariant metrics on Lie groups from several complementary perspectives. On the one hand, fixing a metric Lie group \( (G,g) \), geodesic completeness can be studied via the associated Euler-Arnold equation on the Lie...

Convenient categories of locales and beyond

2026-01-15

Speaker: Martin Hyland (Univ. Cambridge, UK)

In classical topology, it is natural to think in terms of function spaces yet the category of topological spaces is not cartesian closed. In 1967, Norman Steered proposed in effect to address that by working within coreflective subcategories which are cartesian closed. The essential idea is...

Free boundary regularity for the obstacle problem

2026-01-20

Speaker: Alessio Figalli (Fields Medal, ETH Zurich, Switzerland)

The classical obstacle problem consists of finding the equilibrium position of an elastic membrane whose boundary is held fixed and constrained to lie above a given obstacle. By classical results of Caffarelli, the free boundary is smooth outside a set of singular points. However, explicit...

The ODE/IM correspondence for the quantum KdV model

2026-01-27

Speaker: Gabriele Degano (Univ. Lisbon, Portugal)

We study the ground state of the quantum KdV model using the ODE/IM correspondence, which relates spectral data of differential equations to integrable structures in quantum field theory. Focusing on a family of anharmonic oscillators, we analyze their spectral determinants and show how they...

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2026-01-28

Speaker: Ilias Ermeidis (Univ. of Göttingen, Germany)

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The dynamics of viscous vortex filaments and the binormal curvature flow

2026-02-02

Speaker: Luis Vega (UPV/EHU & BCAM, Spain)

I'll present some recent work about the connection of vortex filaments/tubes that move according to Navier Stokes Equation and the binormal curvature flow of curves in 3d. This is a joint work with Mikel Ispizua and Marco A. Fontelos....

Torsion theory in a non-pointed context

2026-02-03

Speaker: Andrea Montoli (Univ. degli Studi di Milano, Italy)

We will discuss a non-pointed version of the notion of torsion theory, in the framework of categories equipped with a posetal monocoreflective subcategory such that the coreflector inverts monomorphisms. We will explore the relationships of such torsion theories with factorization systems...

Degenerate versions of hypergeometric Bernoulli and Euler polynomials

2026-02-25

Speaker: Yamilet Quintana (Universidad Carlos III de Madrid, Spain)

We introduce degenerate versions of the hypergeometric Bernoulli and Euler polynomials. We demonstrate that they form \( \Delta_\lambda \)-Appell sets and provide some of their algebraic properties, including inversion formulas, as well as the associated matrix formulation. Additionally, we...

An Auslander-Buchsbaum formula for higher Auslander algebras

2026-02-25

Speaker: Tiago Cruz (Univ. of Stuttgart, Germany)

The Auslander-Buchsbaum formula is a powerful tool in commutative algebra connecting the concepts of depth and projective dimension. One of its most meaningful applications is the famous result which states that a local commutative ring is regular if and only if it has finite global...

The Value of Errors in Proofs (a fascinating journey from Turing's 1936 R \(\neq\) RE to the 2020 breakthrough of MIP* = RE)

2026-03-01

Speaker: Avi Wigderson (Abel Prize, Turing Award, IMU Abacus Medal, Institute for Advanced Study, Princeton Univ., USA)

In 2020, a group of theoretical computer scientists posted a paper on the Arxiv with the strange-looking title "MIP* = RE", impacting and surprising not only computational complexity theory but also some areas of math and physics. Specifically, it resolved, in the negative, the "Connes'...

Yet another characterization of discrete classical orthogonal polynomials on linear lattices?

2026-03-12

Speaker: Guillermo Gordillo-Núñez (CMUC, University of Coimbra)

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Partial regularity in nonlocal problems

2026-04-16

Speaker: Giuseppe Mingione (Università di Parma, Italy)

The theory of partial regular regularity for elliptic systems replaces the classical De Giorgi-Nash-Moser one for scalar equations asserting that solutions are regular outside a negligible closed subset called the singular set. Eventually, Hausdorff dimension estimates on such a set can be...

Block eigenvalues and matrix roots of matrix polynomials: Applications to ordinary differential matrix equations and matrix differences equations

2026-04-17

Speaker: Manuel A. Facas Vicente & José Vitória (Univ. Coimbra, Portugal)

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2026-05-12

Speaker: Juan Gabriel Calvo (Univ. of Costa Rica, Costa Rica)

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2026-06-16

Speaker: Rafael Díaz Fuentes (Università di Cagliari, Italy)

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2026-06-19

Speaker: Irene Fonseca (Carnegie Mellon University, USA)

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