On Complex Characters of $SL(4,q)$

Abstract

In this paper we restricted the complex characters of $GL(4,p)$ down to $SL(4,q)$ by using the character values on classes of $GL(4,p)$. Using a version of Clifford's Theorem making use of properties of roots of unity, we determine which restricted characters are irreducible, which of them are split and how many parts they split up into irreducible complex characters of $SL(4,q)$ and degrees of conjugate irreducible components of all reducible restricted characters.