Conjugacy-separable implies characters of finite-dimensional representations over complex numbers separate conjugacy classes
Statement
Suppose is a Conjugacy-separable group (?), i.e., any two distinct conjugacy classes can be separated in a finite quotient group. Then, given any two distinct conjugacy classes, there is a finite-dimensional representation of over the field of complex numbers such that the character value of the representation at the two conjugacy classes is different.
In fact, instead of taking , we can simply take the cyclotomic algebraic closure of the rational numbers, i.e., the field obtained by adjoining all roots of unity to the rational numbers.
Facts used
- Sufficiently large implies splitting: This says that a field that contains all primitive roots of unity where is the exponent of the group is a splitting field.
- Splitting implies characters separate conjugacy classes
Proof
PLACEHOLDER FOR INFORMATION TO BE FILLED IN: [SHOW MORE]