The A-core and A-cover of a group

• This paper provides a comprehensive investigation of the cellular approximation functor cell(A) G, in the category of groups. approximating a group G by a group A. We also study related notions such as A-injection, A-generation and A-constructibility of a group G and we find several interesting connections with the Schur multiplier H-2(G, Z). Our constructions are direct and are given in a slow and detailed manner.

Keyword

A-generation

A-constructibility

A-injection

A-cellular cover

Central extensions

Schur multiplier

equivalences

Publication and Content Type

ref (subject category)

art (subject category)