Definition:Character (Representation Theory)

Definition
Let $\struct {G, \cdot}$ be a finite group.

Let $V$ be a finite dimensional $k$-vector space.

Consider a linear representation $\rho: G \to \GL V$ of $G$.

Let $\map \tr {\map \rho g}$ denote the trace of $\map \rho g$.

The character associated with $\rho$ is defined as:
 * $\chi: G \to k$

where $\map \chi g = \map \tr {\map \rho g}$, the trace of $\map \rho g$; which is a linear automorphism of $V$.

Note
If $G$ is abelian, then this definition for character is equivalent to the one of character.

Also see

 * Definition:Character Table