A characterization of weak Radon-Nikodym sets in dual Banach spaces (Q1821300)

\textit{L. Riddle} [Proc. Amer. Math. Soc. 86, 433-438 (1982; Zbl 0503.46033)] gave a characterization of weak*-compact absolutely convex sets with the weak Radon-Nikodym property in terms of \(\delta\)-Rademacher trees. The aim of our paper is to give a generalization of this result. That is, adopting an argument similar to one employed in [Publ. Res. Inst. Math. Sci. 21, 921-941 (1985; Zbl 0594.46014)], we can present a following characterization of weak*-compact convex (not necessarily absolutely convex) sets with the weak Radon-Nikodym property: Let K be a weak*-compact convex subset of a dual Banach space X*. Then K is a weak Radon-Nikodym set if and only if it contains no \(\delta\)-Rademacher tree.