Centre for Mathematics, University of Coimbra

Seminars

Rethinking rank: from linear algebra to additive categories

2026-04-08

Speaker: Teresa Conde (University of Bielefeld, Germany)

The concept of a rank function on an additive category with cokernels, or more generally, on one admitting finite weak cokernel resolutions, generalises the classical notion of a Sylvester rank function on a ring, which itself extends familiar invariants such as the dimension of a vector...

Quantization and Hamiltonian flows in imaginary time

2026-04-15

Speaker: João Pimentel Nunes (IST, Univ. Lisboa)

I will review the application of Hamiltonian flows in imaginary time to problems in geometric quantization. I will describe applications to symplectic toric manifolds and, time permitting, will also describe how this framework provides a geometric interpretation of the Peter-Weyl theorem....

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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Contact sub-Riemannian structures as non-transitive Cartan geometries

2026-04-22

Speaker: João Nuno Mestre (CMUC)

Cartan geometries are structures on manifolds which are infinitesimally modelled on homogeneous spaces. For example, Riemannian structures are infinitesimally modelled by the euclidean space. The classical theory deals with "transitive" Cartan geometries, where the infinitesimal model is the...

On the protomodular and Mal'tsev properties for varieties of ordered algebras

2026-04-28

Speaker: Diana Rodelo (Univ. do Algarve)

The aim of the talk is to study the notions of lax protomodular category [1] and \( \mathsf{Ord} \)-Mal'tsev category [2] in the context of (coherent) varieties of (pre)ordered algebras and to compare them, as has been done in the non-ordered context. We characterise varieties of ordered...

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2026-05-04

Speaker: Soichiro Fujii (Kyoto Univ., Japan)

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2026-05-04

Speaker: Zeinab Galal (Kyoto Univ., Japan

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Can a non-trivial isometric quotient of the unit n-sphere be made arbitrarily small?

2026-05-07

Speaker: Claudio Gorodski (Univ. São Paulo, Brazil)

We will explain our proof of the existence of \( \varepsilon >0 \) such that every quotient of the unit sphere \( S^n (n\geq 2) \) by a isometric group action has diameter zero or at least \( \varepsilon \). The novelty is the independence of \( \varepsilon \) from \( n \). The...

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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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Using symplectic groupoid multiplication for Poisson integrators

2026-06-24

Speaker: Alejandro Cabrera (Uni. Politècnica de Catalunya, Spain)

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2026-10-22

Speaker: Thomas Kriecherbauer (Univ. of Bayreuth, Germany)

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