Arens extensions of disjointness preserving multilinear operators on Riesz spaces and Banach lattices
Geraldo Botelho, Luis Alberto Garcia, Vinícius C. C. Miranda
TL;DR
This paper investigates when Arens extensions of regular disjointness preserving $m$-linear operators between Riesz spaces and Banach lattices preserve disjointness. It proves two main sufficient conditions: (a) finite lattice rank of the operator, and (b) the dual of the codomain has a Schauder basis of disjointness preserving functionals, which guarantee that all AR extensions $AR_m^{rho}(A)$ preserve disjointness. Linear-case results show that the second adjoint $T''$ of a disjointness preserving operator is disjointness preserving when the target is Archimedean (and hence for Banach lattices). The work extends prior results on Riesz multimorphisms and Arens regularity and provides applicable criteria for common Banach lattices such as $c_0$, $\, ext{l}_p$, etc.
Abstract
Let $E_1, \ldots, E_m$ be (non necessarily Archimedean) Riesz spaces, let $F$ be an Archimedean Riesz space and let $A \colon E_1 \times \cdots \times E_m \to F$ be a regular disjointness preserving $m$-linear operator. We prove that all Arens extensions of $A$ are disjointness preserving if either $A$ has finite lattice rank or the spaces are Banach lattices and $F^*$ has a Schauder basis consisting of disjointness preserving functionals.
