Stabilizer (original) (raw)
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Let be a permutation group on a set
and
be an element of
. Then
(1) |
---|
is called the stabilizer of and consists of all the permutations of
that produce group fixed points in
, i.e., that send
to itself. For example, the stabilizer of 1 and of 2 under the permutation group
is both
, and the stabilizer of 3 and of 4 is
.
More generally, the subset of all images of under permutations of the group
(2) |
---|
is called the group orbit of in
.
A group's action on an group orbit through is transitive, and so is related to its isotropy group. In particular, the cosets of the isotropy subgroup correspond to the elements in the orbit,
(3) |
---|
where is the orbit of
in
and
is the stabilizer of
in
. This immediately gives the identity
| | (4) |
| ------------------------------------------------------------------------------------------------------ | --- |
where denotes the order of group
(Holton and Sheehan 1993, p. 27).
See also
Group Action, Group Fixed Point, Group Orbit, Permutation Group
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References
Holton, D. A. and Sheehan, J. Ch. 6 in The Petersen Graph. Cambridge, England: Cambridge University Press, p. 26, 1993.
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Cite this as:
Weisstein, Eric W. "Stabilizer." FromMathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Stabilizer.html