Centre for Mathematics, University of Coimbra

Seminars

Describing good objects in categories with weak algebraic properties

2025-05-13

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

With the initial motivation of looking for a categorical characterization of groups among monoids, we introduced some conditions on objects in general categories, describing good algebraic properties holding locally for these objects although not globally in the category. These conditions,...

Generalized conjugacy separability in extensions of groups

2025-05-13

Speaker: André Carvalho (CMUP, Univ. Porto)

Separability properties in groups can be seen as an algebraic analogue of classical decision problems in finitely presented groups, as an argument by Mal'cev shows that if a subset S of a finitely presented group is recursively enumerable, separable and its image under a surjective...

Normed categories

2025-05-20

Speaker: Walter Tholen (York Univ., Toronto, Canada)

In this talk we explore Lawvere's notion of normed category through the lens of easily understood small and large example categories. Cauchy convergence of sequences in such categories gets presented as a natural extension of familiar concepts taught in Calculus and Functional Analysis, but...

Self-dual aspects of semi-abelian categories

2025-05-20

Speaker: Tim Van der Linden (Univ. catholique de Louvain and Vrije Univ. Brussel, Belgium)

The aim of this talk is to introduce di-exact categories [3], which are defined by a simple axiom system capturing self-dual aspects of the context of Janelidze-Márki-Tholen semi-abelian categories [2,1]. A Borceux-Bourn homological category [1] is Barr-exact if and only if it is di-exact....

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2025-06-17

Speaker: Alfredo Costa (CMUC, Univ. Coimbra)

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2025-06-17

Speaker: Célia Borlido (CMUC, Univ. Coimbra)

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