Universal central extensions of precrossed modules and Milnor's relative K2

[EN] We characterize the universal central extension of a perfect precrossed module giving two descriptions, one in terms of non-abelian tensor products of groups and other in terms of projective presentations. As application to relative algebraic K-theory, we obtain that Milnor's absolute and...

Descripción completa

Detalles Bibliográficos
Autores: Arias Mosquera, Daniel, Ladra, Manuel, R.-Grandjeán, Alfredo
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2003
País:España
Institución:Universidad de León
Repositorio:BULERIA. Repositorio Institucional de la Universidad de León
OAI Identifier:oai:buleria.unileon.es:10612/21064
Acceso en línea:https://www.sciencedirect.com/science/article/pii/S0022404903000653
https://hdl.handle.net/10612/21064
Access Level:acceso abierto
Palabra clave:Matemáticas
Steinberg group
Universal central extension
Precrossed module
Relative K-theory
Non-Abelian tensor product
1201.03 Teoría de Categorías
1201.06 Grupos, Generalidades
1201.07 Álgebra Homológica
Descripción
Sumario:[EN] We characterize the universal central extension of a perfect precrossed module giving two descriptions, one in terms of non-abelian tensor products of groups and other in terms of projective presentations. As application to relative algebraic K-theory, we obtain that Milnor's absolute and relative K2 groups are the kernel of the universal central extension of the precrossed module determined by the groups of the elementary matrices of a ring and relative to an ideal, respectively.