Homology, Homotopy and Applications
Volume 4 (2002)
Extensions of symmetric cat-groups
Pages: 103 – 162
This paper is an attempt to study extensions of symmetric categorical groups from a structural point of view. Using in a systematic way bilimits in the 2-category of symmetric categorical groups, we develop a theory which closely follows the classical theory of abelian group extensions. The basic results are established for any proper class of extensions, and a cohomological classification is obtained for those extensions whose epi part has a categorical section.
symmetric categorical groups, extensions, bilimits, homological algebra
2010 Mathematics Subject Classification
18D10, 18Gxx, 20L05