(Prior to publication, this paper should be cited as arXiv:1603.01175.)
We exhibit nine sequences of permutation polynomials of the form X+γTr(Xk over the finite field F of order qn, where γ ∈ F and Tr denotes the trace map from F to its order-q subfield. Computation of all permutation polynomials of this form over fields of size less than 5000 suggests that our examples comprise all examples except for some trivial cases and a few sporadic examples. Intriguingly, our proofs of the different sequences use various different methods, including a new variant of Dobbertin's method among others.
Michael Zieve: home page publication list