Incomplete character sums and a special class of permutations
Stephen D. Cohen, Harald Niederreiter, Igor E. Shparlinski, Michael E. Zieve · Journal de Théorie des Nombres de Bordeaux · 2001
We present a method of bounding incomplete character sums for finite abelian groups with arguments produced by a first-order recursion. This method is particularly effective if the recursion involves a special type of permutation called an ℛ -orthomorphism. Examples of ℛ -orthomorphisms are given.