Centre for Mathematics, University of Coimbra

Seminars

Dual presentations of locales

2026-03-17

Speaker: Graham Manuell (Stellenbosch Univ., South Africa)

Just as usual presentations of frames allow us to define frames using sets of generators and relations, we will discuss how to define frames using compact Hausdorff locales of generators and relations. I will explain how to present a compact Hausdorff locale in terms of itself and describe...

Perfectly regular frames

2026-03-17

Speaker: Ana Belén Avilez (Chapman Univ., USA)

Cozero elements of a frame play an important role in point-free topology. The set of cozero elements, \( \mathrm{Coz}L \), of a frame \( L \) is a sub \( \sigma \)-frame of \( L \) (that is, a sublattice closed under countable suprema and finite infima). Moreover, the lattice \(...

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2026-03-20

Speaker: Tiago Picon (Universidade de São Paulo, Brazil)

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2026-03-27

Speaker: Sven Jarohs (Goethe-Universität, Frankfurt, Germany)

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Higgs bundles and geometric structures through the Non-abelian Hodge Correspondence

2026-04-01

Speaker: Pedro M. Silva (Univ. Lisboa)

Higgs bundles are holomorphic objects which have become useful for understanding representations of the fundamental group of a closed surface into a Lie group. In this talk, we will present an overview of their theory, and how the Non-abelian Hodge correspondence can be used to study...

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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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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2026-10-22

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

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