On Clifford's theorem and ramification indices for symplectic modules over a finite field

Abstract

Let K be a field, G a finite group. Let V be an (irreducible) KG-module, where KG is the group algebra consisting of all formal sums . The action of on α = ∑aθg on element ν ∈ V obeys the rule If H is a subgroup of G, then, restricting the action of G on V to H, V is also a KH-module. Notation: VH.