On the extension of positive linear functionals.
In this note we prove that there exists a Carathéodory vector lattice such that and . This yields that is a solution of the Schröder-Bernstein problem for Carathéodory vector lattices. We also show that no Carathéodory Banach lattice is a solution of the Schröder-Bernstein problem.
In this paper we deal with the vector lattice of all elementary Carathéodory functions corresponding to a generalized Boolean algebra .
Let be the Banach space of real measures on a -ring , let be its dual, let be a quasi-complete locally convex space, let be its dual, and let be an -valued measure on . If is shown that for any there exists an element of such that for any and that the mapis order continuous. It follows that the closed convex hull of is weakly compact.
We first study positivity in C*-modules using tripotents ( = partial isometries) which are what we call open. This is then used to study ordered operator spaces via an "ordered noncommutative Shilov boundary" which we introduce. This boundary satisfies the usual universal diagram/property of the noncommutative Shilov boundary, but with all the arrows completely positive. Because of their independent interest, we also systematically study open tripotents and their properties.
It is proved by an order theoretical and purely algebraic method that any order bounded orthosymmetric bilinear operator where and are Archimedean vector lattices is symmetric. This leads to a new and short proof of the commutativity of Archimedean almost -algebras.
Let be a compact space and let be the Banach lattice of real-valued continuous functions on . We establish eleven conditions equivalent to the strong compactness of the order interval in , including the following ones: (i) consists of isolated points of ; (ii) is pointwise compact; (iii) is weakly compact; (iv) the strong topology and that of pointwise convergence coincide on ; (v) the strong and weak topologies coincide on . Moreover, the weak topology and that of pointwise convergence...