Difference between revisions of "Automorphism group of a group"

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==Definition==
 
==Definition==
  

Revision as of 00:22, 31 December 2007

This article is about a basic definition in group theory. The article text may, however, contain advanced material.
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Definition

Symbol-free definition

The automorphism group of a group is defined as a group whose elements are all the automorphisms of the base group, and where the group operation is composition of automorphisms. In other words, it gets a group structure as a subgroup of the group of all permutations of the group.

Definition with symbols

The 'automorphism group of a group G, denoted Aut(G), is a set whose elements are automorphisms \sigma:G \to G, and where the group multiplication is composition of automorphisms. In other words, its group structure is obtained as a subgroup of Sym(G), the group of all permutations on G.