English

The Kaplansky condition and rings of almost stable range 1

Commutative Algebra 2011-07-18 v1

Abstract

We present some variants of the Kaplansky condition for a K-Hermite ring RR to be an elementary divisor ring; for example, a commutative K-Hermite ring RR is an EDR iff for any elements x,y,zRx,y,z\in R such that (x,y)=(1)(x,y)=(1), there exists an element λR\lambda\in R such that x+λy=uvx+\lambda y=uv, where (u,z)=(v,1z)=(1)(u,z)=(v,1-z)=(1). We present an example of a a B\'ezout domain that is an elementary divisor ring, but it does not have almost stable range 1, thus answering a question of Warren Wm. McGovern.

Keywords

Cite

@article{arxiv.1107.3000,
  title  = {The Kaplansky condition and rings of almost stable range 1},
  author = {Moshe Roitman},
  journal= {arXiv preprint arXiv:1107.3000},
  year   = {2011}
}