The direction functor for Schreier extensions of monoids

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Ambra, Stefano, Montoli, Andrea, Rodelo, Diana
Format: Preprint
Veröffentlicht: 2026
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866911464806154240
author Ambra, Stefano
Montoli, Andrea
Rodelo, Diana
author_facet Ambra, Stefano
Montoli, Andrea
Rodelo, Diana
contents We observe that the process of associating an action to any Schreier extension of monoids with commutative and cancellative kernel is functorial. We show that this functor is a generalisation of the direction functor, used to give a categorical description of non-abelian cohomology in terms of extensions. We further prove that our functor is a conservative, product preserving cofibration and from this we conclude that its fibres are endowed with a canonical symmetric monoidal structure. The commutative monoids obtained as connected components of these symmetric monoidal categories are isomorphic to Patchkoria second cohomology monoids of a monoid with coefficients in semimodules.
format Preprint
id arxiv_https___arxiv_org_abs_2602_20755
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle The direction functor for Schreier extensions of monoids
Ambra, Stefano
Montoli, Andrea
Rodelo, Diana
Category Theory
18G50, 20J06, 20M50, 18E13, 18C05
We observe that the process of associating an action to any Schreier extension of monoids with commutative and cancellative kernel is functorial. We show that this functor is a generalisation of the direction functor, used to give a categorical description of non-abelian cohomology in terms of extensions. We further prove that our functor is a conservative, product preserving cofibration and from this we conclude that its fibres are endowed with a canonical symmetric monoidal structure. The commutative monoids obtained as connected components of these symmetric monoidal categories are isomorphic to Patchkoria second cohomology monoids of a monoid with coefficients in semimodules.
title The direction functor for Schreier extensions of monoids
topic Category Theory
18G50, 20J06, 20M50, 18E13, 18C05
url https://arxiv.org/abs/2602.20755