Representation Theory: Home Page

Example sheets, solution sheets and other material related to the course will be posted here. Let f(g) be the number of ways of expressing an element g of a group G as a commutator. Here is a proof of the formula (which I mentioned in lectures) giving the class function f as a linear combination of irreducible characters. Using this formula, the fact that the degree of every irreducible character divides the order of the group is easily seen to be equivalent to the fact that f is a character. Is there a direct way to see that it's a character?