A comprehensive connection between the basic results and properties derived from two kinds of topologies for a random locally convex module

Tiexin Guo

Published 2009-08-13, updated 2010-06-21Version 10

The purpose of this paper is to make a comprehensive connection between the basic results and properties derived from the two kinds of topologies (namely the $(\epsilon,\lambda)-$topology introduced by the author and the stronger locally $L^{0}-$convex topology recently introduced by Filipovi$\acute{c}$ et. al) for a random locally convex module. First, we give an extremely simple proof of the known Hahn-Banach extension theorem of $L^{0}-$linear functions as well as its continuous variants. Then we give the essential relations between the hyperplane separation theorems in [Filipovi$\acute{c}$ et. al, J. Funct. Anal.256(2009)3996--4029] and a basic strict separation theorem in [Guo et. al, Nonlinear Anal. 71(2009)3794--3804]: in the process obtain a useful and surprising fact that a random locally convex module with the countable concatenation property must have the same completeness under the two topologies! Based on the relation between the two kinds of completeness, we go on to present the central part of this paper: we prove that most of the previously established deep results of random conjugate spaces of random normed modules under the $(\epsilon,\lambda)-$topology are still valid under the locally $L^{0}-$convex topology, which considerably enriches financial applications of random normed modules.