Non-modular implies class-determining
Statement
Suppose is a finite group and is a field whose characteristic is either zero or a prime not dividing the order of . Then, is a Class-determining field (?) for : given two representations such that is conjugate to for every , it is true that and are equivalent linear representations, i.e., there exists a matrix satisfying for all .
Facts used
- Non-modular implies character-determining: This basically says that the character determines the representation.
- Character-determining implies class-determining: This says that if the character determines the representation, then knowing the conjugacy class of the image of every element suffices.
Proof
The proof follows from facts (1) and (2).