Some remarks on pullbacks in Gumm categories
Category Theory
2014-08-07 v1
Abstract
We extend some properties of pullbacks which are known to hold in a Mal'tsev context to the more general context of Gumm categories. The varieties of universal algebras which are Gumm categories are precisely the congruence modular ones. These properties lead to a simple alternative proof of the known property that central extensions and normal extensions coincide for any Galois structure associated with a Birkhoff subcategory of an exact Goursat category.
Cite
@article{arxiv.1408.1342,
title = {Some remarks on pullbacks in Gumm categories},
author = {Marino Gran and Diana Rodelo},
journal= {arXiv preprint arXiv:1408.1342},
year = {2014}
}
Comments
12 pages