English

Characterization of Hilbertizable spaces via convex functions

Functional Analysis 2025-06-11 v1 Optimization and Control

Abstract

We show that the existence of a strongly convex function with a Lipschitz derivative on a Banach space already implies that the space is isomorphic to a Hilbert space. Similarly, if both a function and its convex conjugate are C2C^2 then the underlying space is also isomorphic to a Hilbert space.

Keywords

Cite

@article{arxiv.2506.04686,
  title  = {Characterization of Hilbertizable spaces via convex functions},
  author = {Nicolas Borchard and Gerd Wachsmuth},
  journal= {arXiv preprint arXiv:2506.04686},
  year   = {2025}
}

Comments

8 pages

R2 v1 2026-07-01T03:00:45.248Z