English

Nondentable Sets in Banach Spaces

Functional Analysis 2020-03-02 v2

Abstract

In his study of the Radon Nikod\'ym property of Banach spaces, Bourgain showed (among other things) that in any closed, bounded, convex set AA that is nondentable, one can find a separated, weakly closed bush. In this note, we prove a generalization of Bourgain's result: in any bounded, nondentable set AA (not necessarily closed or convex) one can find a separated, weakly closed approximate bush. Similarly, we obtain as corollaries the existence of AA-valued quasimartingales with sharply divergent behavior.

Keywords

Cite

@article{arxiv.1910.11962,
  title  = {Nondentable Sets in Banach Spaces},
  author = {S. J. Dilworth and Chris Gartland and Denka Kutzarova and N. Lovasoa Randrianarivony},
  journal= {arXiv preprint arXiv:1910.11962},
  year   = {2020}
}

Comments

9 pages

R2 v1 2026-06-23T11:55:27.125Z