文摘
A well-known result of Carlitz, that any permutation polynomial (x) of a finite field is a composition of linear polynomials and the monomial xq−2, implies that (x) can be represented by a polynomial , for some n0. The smallest integer n, such that represents (x) is of interest since it is the least number of “inversions” xq−2, needed to obtain (x). We define the Carlitz rank of (x) as n, and focus here on the problem of evaluating it. We also obtain results on the enumeration of permutations of with a fixed Carlitz rank.