Good rings and homogeneous polynomials
Abstract
In 2011, Khurana, Lam and Wang define the following property. (*)A commutative unital ring A satisfies the property ''power stable range one'' if for all a, b A with aA + bA = A there are an integer N = N (a, b) 1 and = (a, b) A such that b N + a A x , the unit group of A. In 2019, Berman and Erman consider rings with the following property (**) A commutative unital ring A has enough homogeneous polynomials if for any k 1 and set S := {p 1 , p 2 , ..., p k } , of primitive points in A n and any n 2, there exists an homogeneous polynomial P (X 1 , X 2 , ..., X n) A[X 1 , X 2 , ..., X n ]) with deg P 1 and P (p i) A x for 1 i k. We show in this article that the two properties (*) and (**) are equivalent and we shall call a commutative unital ring with these properties a good ring. When A is a commutative unital ring of pictorsion as defined by Gabber, Lorenzini and Liu in 2015, we show that A is a good ring. Using a Dedekind domain we built by Goldman in 1963,we show that the converse is false.
Cite
@article{arxiv.1907.05655,
title = {Good rings and homogeneous polynomials},
author = {J. Fresnel and Michel Matignon},
journal= {arXiv preprint arXiv:1907.05655},
year = {2020}
}
Comments
The paper is reorganized, some historical comments are added and some proofs are streamlined following referee's suggestions