English

A note on smooth rotund norms which are not midpoint locally uniformly rotund

Functional Analysis 2025-04-08 v2

Abstract

We prove that every separable infinite-dimensional Banach space admits a G\^ateaux smooth and rotund norm which is not midpoint locally uniformly rotund. Moreover, by using a similar technique, we provide in every infinite-dimensional Banach space with separable dual a Fr\'echet smooth and weakly uniformly rotund norm which is not midpoint locally uniformly rotund. These two results provide a positive answer to some open problems by A. J. Guirao, V. Montesinos, and V. Zizler.

Keywords

Cite

@article{arxiv.2402.13869,
  title  = {A note on smooth rotund norms which are not midpoint locally uniformly rotund},
  author = {Carlo Alberto De Bernardi and Alessandro Preti and Jacopo Somaglia},
  journal= {arXiv preprint arXiv:2402.13869},
  year   = {2025}
}