MATHEMATICS

G-groups

Alberto Facchini, Padova University, Italy

9:30 - 10:30

Let G be a group. A G-group is a pair (H,f), where H is a group and f:G --> Aut(H) is a group homomorphism. The category G-Grp of all G-groups shows a behaviour that is a very pleasant combination of the behaviour of groups and that of left modules over a ring. We will describe several properties of this category G-Grp. In particular, the existence, discovered by Remak, of the central automorphism in the statement of the classical Krull-Schmidt Theorem for finite groups has a natural explanation interpreting this result in the category G-Grp.