Normalities and commutators
- Autori: Mantovani, S; Metere, G
- Anno di pubblicazione: 2010
- Tipologia: Articolo in rivista (Articolo in rivista)
- Parole Chiave: Normal subobject; Ideal; Commutator; Semi-abelian
- OA Link: http://hdl.handle.net/10447/74837
Abstract
We first compare several algebraic notions of normality, from a categorical viewpoint. Then we introduce an intrinsic description of Higgins' commutator for ideal-determined categories, and we define a new notion of normality in terms of this commutator. Our main result is to extend to any semi-abelian category the following well-known characterization of normal subgroups: a subobject K is normal in A if. and only if, {[A, K] <= K. (C) 2010 Elsevier Inc. All rights reserved.}