SL(n) Examples with Slightly Composite n
Nicholas M. Katz · Princeton University Press eBooks · 2012
This chapter continues to study the object N of Theorem 21.1. Thus, k is a finite field of characteristic p, ψ a nontrivial additive character of k, f(x) = f(x)=∑i=−baAixi∈k[x,1/x]Aᵢxⁱ ɛ k[x, 1/x] is a Laurent polynomial of “bidegree” (a, b), with a; b both ≤ 1 and both prime to p. It is assumed that f(x) is Artin–Schreier reduced. It takes for N the object N:ℒψ(f(x))(1/2)[1]∈ρarith.