Janelidze, George What is a double central extension? (The question was asked by Ronald Brown). (English) Zbl 0762.18003 Cah. Topologie Géom. Différ. Catég. 32, No. 3, 191-201 (1991). The author obtains an answer to this question for groups by applying his Galois theory in general categories to a particular category: the arrow category of the category of groups. Reviewer: R.H.Street (North Ryde) Cited in 25 Documents MSC: 18A99 General theory of categories and functors 20J15 Category of groups 18B99 Special categories Keywords:central extension; Galois theory in general categories; arrow category of the category of groups × Cite Format Result Cite Review PDF Full Text: Numdam EuDML References: [1] 1 R. Brown & G.J. Ellis , ’Hopf formulae for the higher homology of a group’ , Bull. London Math. Soc. 20 ( 1988 ) 124 - 128 . MR 924238 | Zbl 0611.20032 · Zbl 0611.20032 · doi:10.1112/blms/20.2.124 [2] 2 G. Janalidze , ’Pure Galois theory in categories’ , J. Algebra 132 ( 1990 ) 270 - 286 . (First version was available as UCNW Preprint 87.20, Bangor , 1987 .) MR 1061480 This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.