On Graded Categorical Groups and Equivariant Group Extensions

@inproceedings{CegarraOnGC,
  title={On Graded Categorical Groups and Equivariant Group Extensions},
  author={Antonio Mart{\'i}nez Cegarra and J. M. Garcı́a-Calcines and Juan Antonio Ortega}
}
In this article we state and prove precise theorems on the homotopy classification of graded categorical groups and their homomorphisms. The results use equivariant group cohomology, and they are applied to show a treatment of the general equivariant group extension problem.