Knowledge in Group theory

Inner and Outer Automorphism

Two types of automorphism i.e. inner and outer automorphism.... Theorem that set of all inner automorphism is a normal Subgroup and two more theorems that phi is automorphism iff G is abelian

Commutator of a group

Definition of commutator of a group and it's theorem and definition of derive group, it's another name is commutative subgroup and it's theorem

Direct product of groups

Definition of direct product of groups, in the direct product, every element of H is commute with every element of K and every element of G is uniquely expressible And more results too

Invariant and characteristic subgroup

If G is a group and G=H×K, then the factor group G/K is isomorphic to H.... Another result that if H and K are cyclic groups then H×K is a cyclic group.... Definition and examples of invariant and characteristic subgroup