Misplaced Pages

Induced character

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.

In mathematics, an induced character is the character of the representation V of a finite group G induced from a representation W of a subgroup HG. More generally, there is also a notion of induction Ind ( f ) {\displaystyle \operatorname {Ind} (f)} of a class function f on H given by the formula

Ind ( f ) ( s ) = 1 | H | t G ,   t 1 s t H f ( t 1 s t ) . {\displaystyle \operatorname {Ind} (f)(s)={\frac {1}{|H|}}\sum _{t\in G,\ t^{-1}st\in H}f(t^{-1}st).}

If f is a character of the representation W of H, then this formula for Ind ( f ) {\displaystyle \operatorname {Ind} (f)} calculates the character of the induced representation V of G.

The basic result on induced characters is Brauer's theorem on induced characters. It states that every irreducible character on G is a linear combination with integer coefficients of characters induced from elementary subgroups.

References

  1. Serre, Jean-Pierre (1977), Linear Representations of Finite Groups, New York: Springer-Verlag, 7.2, Proposition 20, ISBN 0-387-90190-6, MR 0450380. Translated from the second French edition by Leonard L. Scott.


Stub icon

This group theory-related article is a stub. You can help Misplaced Pages by expanding it.

Categories:
Induced character Add topic