Centre of a group: Difference between revisions

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(def in terms of trivial conjugation)
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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.



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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.