Singular extensions and the second cohomology categorical group

被引:0
|
作者
Garzon, A. R. [1 ]
机构
[1] Univ Granada, Fac Ciencias, Dept Algebra, E-18071 Granada, Spain
关键词
(Symmetric) categorical group; Categorical action; Non-functorial derivation; 2-exactness; Cohomology categorical group; Singular extension; CLASSIFYING-SPACES; SCHREIER THEORY; NERVES;
D O I
10.1007/s40062-016-0135-1
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
We give a classification of the 2-groupoid of singular extensions of categorical groups by means of a second cohomology categorical group, whose definition uses the notion of nerve of a categorical group. This second cohomology is, then, shown to be involved in a five term 2-exact sequence a la Hochschild-Serre which is associated with any essentially surjective homomorphism of categorical groups.
引用
收藏
页码:447 / 485
页数:39
相关论文
共 50 条