Noether's normalization in skew polynomial rings
Rings and Algebras
2025-07-02 v2
Abstract
We study Noether's normalization lemma for finitely generated algebras over a division algebra. In its classical form, the lemma states that if is a proper ideal of the ring of polynomials over a field , then the quotient ring is a finite extension of a polynomial ring over . We prove that the lemma holds when is the ring of polynomials in central variables over a division algebra . We provide examples demonstrating that Noether's normalization may fail for the skew polynomial ring with respect to commuting automorphisms of . We give a sufficient condition for under which the normalization lemma holds for such ring. In the case where is a field, this sufficient condition is proved to be necessary.
Cite
@article{arxiv.2407.12686,
title = {Noether's normalization in skew polynomial rings},
author = {Elad Paran and Thieu N. Vo},
journal= {arXiv preprint arXiv:2407.12686},
year = {2025}
}