Reference request: Representation theory over fields of characteristic zero Many representation theory textbooks and online resources work with the field of complex numbers or more generally algebraically closed fields of characteristic zero. I am looking for a good textbook on representation theory which works with fields of characteristic zero directly from the beginning. (In case there are many such textbooks, I would prefer "modern" ones which emphasize the theory of non-commutative algebras; it should really be the opposite of Fulton-Harris.) In particular, it should mention the classification of irreducible representations of symmetric groups over $\mathbb{Q}$, and there should be more than just a side remark that those over $\mathbb{C}$ descend to  $\mathbb{Q}$.

The book "The representation theory of the symmetric group" (Encyclopedia of
Mathematics and its Applications, Vol. 16, Addison-Wesley, Reading, Mass., 1981), by Gordon James and Adalbert Kerber, develops the characteristic zero representation theory of symmetric groups over $\mathbb{Q}$. In particular it has a theorem (Theorem 2.1.12) explicitly stating that every field is a splitting field for $S_n$.
