Centre of a group: Difference between revisions
Jump to navigation
Jump to search
imported>Richard Pinch (def in terms of trivial conjugation) |
imported>Chris Day No edit summary |
||
Line 1: | Line 1: | ||
{{subpages}} | |||
In [[group theory]], the '''centre of a group''' is the subset of elements which [[commutativity|commute]] with every element of the group. | In [[group theory]], the '''centre of a group''' is the subset of elements which [[commutativity|commute]] with every element of the group. | ||
Revision as of 11:27, 13 February 2009
In group theory, the centre of a group is the subset of elements which commute with every element of the group.
Formally,
The centre is a subgroup, which is normal and indeed characteristic. It may be described as the set of elements by which conjugation is trivial (the identity map); this shows the centre as the kernel of the homomorphism to G to its inner automorphism group.
See also
References
- Marshall Hall jr (1959). The theory of groups. New York: Macmillan, 14.