An elementary description of $K_1(R)$ without elementary matrices
K-Theory and Homology
2019-10-11 v2
Abstract
Let be a ring with unit. Passing to the colimit with respect to the standard inclusions (which add a unit vector as new last row and column) yields, by definition, the stable linear group ; the same result is obtained, up to isomorphism, when using the "opposite" inclusions (which add a unit vector as new first row and column). In this note it is shown that passing to the colimit along both these families of inclusions simultaneously recovers the algebraic -group of~, giving an elementary description that does not involve elementary matrices explicitly.
Cite
@article{arxiv.1910.02771,
title = {An elementary description of $K_1(R)$ without elementary matrices},
author = {Thomas Huettemann and Zuhong Zhang},
journal= {arXiv preprint arXiv:1910.02771},
year = {2019}
}
Comments
2 pages; v2: two variations of result discussed