English

Generation of the special linear group by elementary matrices in some measure Banach algebras

Functional Analysis 2022-03-08 v5 Group Theory K-Theory and Homology Rings and Algebras

Abstract

For a commutative unital ring RR, and nNn\in \mathbb{N}, let SLn(R)\textrm{SL}_n(R) denote the special linear group over RR, and En(R)\textrm{E}_n(R) the subgroup of elementary matrices. Let M+{\mathcal{M}}^+ be the Banach algebra of all complex Borel measures on [0,+)[0,+\infty) with the norm given by the total variation, the usual operations of addition and scalar multiplication, and with convolution. It is shown that SLn(A)=En(A)\textrm{SL}_n(A)=\textrm{E}_n(A) for Banach subalgebras AA of M+{\mathcal{M}}^+ that are closed under the operation M+μμt{\mathcal{M}}^+\owns \mu \mapsto \mu_t, t[0,1]t\in [0,1], where μt(E):=E(1t)xdμ(x)\mu_t(E):=\int_E (1-t)^x d\mu(x) for t[0,1)t\in [0,1), and Borel subsets EE of [0,+)[0,+\infty), and μ1:=μ({0})δ\mu_1:=\mu(\{0\})\delta, where δM+\delta\in {\mathcal{M}}^+ is the Dirac measure. Many illustrative examples of such Banach algebras AA are given. An example of a Banach subalgebra AM+A\subset {\mathcal{M}}^+, that does not possess the closure property above, but for which SLn(A)=En(A)\textrm{SL}_n(A)=\textrm{E}_n(A) neverthess holds, is also given.

Keywords

Cite

@article{arxiv.2105.07676,
  title  = {Generation of the special linear group by elementary matrices in some measure Banach algebras},
  author = {Amol Sasane},
  journal= {arXiv preprint arXiv:2105.07676},
  year   = {2022}
}

Comments

21 pages, 1 figure. Some typos corrected