Centre for Mathematics, University of Coimbra

Seminars

Algebra and Combinatorics

Abstract G-structures

2026-02-20

Speaker: Pedro Pessoa (CMUC, UC|UP PhD student)

We will give a more general definition of G structure via soldering forms. Then we will use this to study the torsion and curvature of G-connections....

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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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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