Characterizations of finite dimensional Archimedean vector lattices
F. Polata,
M. A. Toumib a Cankiri Karatekin University, Faculty of Science, Department of Mathematics
b University of Carthage, Faculty of Science of Bizerte, Department of Mathematics
Abstract:
In this paper, we give some necessary and sufficient conditions for an Archimedean vector lattice
$A$ to be of finite dimension. In this context, we give three characterizations. The first one contains the relation between the vector lattice
$A$ to be of finite dimension and its universal completion
$A^u$. The second one shows that the vector lattice
$A$ is of finite dimension if and only if one of the following two equivalent conditions holds : (a) every maximal modular algebra ideal in
$A^u$ is relatively uniformly complete or (b)
$\mathrm{Orth}\,(A,A^u)=Z(A,A^u)$ where
$\mathrm{Orth}\,(A,A^u)$ and
$Z(A,A^u)$ denote the vector lattice of all orthomorphisms from
$A$ to
$A^u$ and the sublattice consisting of orthomorphisms
$\pi$ with
$|\pi(x)|\leq\lambda|x|$ $(x\in A)$ for some
$0\leq\lambda\in\mathbb{R}$, respectively. It is well-known that any universally complete vector lattice
$A$ is of the form
$C^\infty (X)$ for some Hausdorff extremally disconnected compact topological space
$X$. The point
$x\in X$ is called
$\sigma$-isolated if the intersection of every sequence of neighborhoods of
$x$ is a neighborhood of
$x$. The last characterization of finite dimensional Archimedean vector lattices is the following. Let
$A$ be a vector lattice and let
$A^{u}(=C^{\infty}\left(X\right))$ be its universal completion. Then
$A$ is of finite dimension if and only if each element of
$X$ is
$\sigma$-isolated. Bresar in [3] raised a question to find new examples of zero product determined algebras. Finally, as an application, we give a positive answer to this question.
Key words:
hyper-Archimedean vector lattice, $f$-algebra, universally complete vector lattice.
UDC:
517.5+517.9
MSC: 47B60,
16E40 Received: 17.07.2017
Language: English
DOI:
10.23671/VNC.2018.2.14725