Published online by Cambridge University Press: 20 November 2018
Let p denote a prime number and let κp denote the finite field of p elements. Let f(x) ∊ κp[x] be of fixed degree d ≥ 2. We suppose that p is also fixed, large compared with d, say, p ≥ p0(d). By V(f) we denote the number of distinct values of f(x), x ∊ κp. We call f maximal if V(f) = p and quasi-maximal if V(f) = p + O(1). Clearly a maximal polynomial is quasi-maximal but it is not known under what conditions the converse holds.