English

On permutations induced by tame automorphisms over finite fields

Algebraic Geometry 2017-05-05 v1 Commutative Algebra

Abstract

The present paper deals with permutations induced by tame automorphisms over finite fields. The first main result is a formula for determining the sign of the permutation induced by a given elementary automorphism over a finite field. The second main result is a formula for determining the sign of the permutation induced by a given affine automorphism over a finite field. We also give a combining method of the above two formulae to determine the sign of the permutation induced by a given triangular automorphism over a finite field. As a result, for a given tame automorphism over a finite field, if we know a decomposition of the tame automorphism into a finite number of affine automorphisms and elementary automorphisms, then one can easily determine the sign of the permutation induced by the tame automorphism.

Keywords

Cite

@article{arxiv.1705.01838,
  title  = {On permutations induced by tame automorphisms over finite fields},
  author = {Keisuke Hakuta},
  journal= {arXiv preprint arXiv:1705.01838},
  year   = {2017}
}

Comments

15 pages, accepted for publication in Acta Mathematica Vietnamica

R2 v1 2026-06-22T19:37:11.449Z