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Responsabili:

Federica Galluzzi  ed  Elena Martinengo
 

Nel calendario si indicano i seminari di geometria algebrica e altre attività di interesse, organizzate dall'Università e dal Politecnico di Torino.

Polyhedra, Lattice Structures, and Extensions of Semigroups

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Data: 

19/05/2021 - 14:30

Aula: 

Aula Virtuale - Webex

Speaker: 

Klaus Altmann

Categoria: 

Seminari di Algebra e Geometria Algebrica

Afferenza: 

Freie Universität Berlin

Descrizione: 

 

Abstract:


For an arbitrary rational polyhedron we consider its decompositions into
Minkowski summands and, dual to this, so-called free extensions of the
associated pair of semigroups. Being free for a pair of semigroups is
equivalent to flatness for the corresponding algebras. Our main result
is phrased in this dual setup: the category of free extensions always
contains an initial object which can be described explicitly.
This result is in contrast to the algebro-geometric version dealing with
deformation theory. The existence of initial free extensions could be
interpreted as the lack of obstructions.
This is joined work with Alexandru Constantinescu and Matej Filip.

Link Webex