English

On the numerical index of polyhedral Banach spaces

Functional Analysis 2024-08-13 v2

Abstract

The computation of the numerical index of a Banach space is an intriguing problem, even in case of two-dimensional real polyhedral Banach spaces. In this article we present a general method to estimate the numerical index of any finite-dimensional real polyhedral Banach space, by considering the action of only finitely many functionals, on the unit sphere of the space. We further obtain the exact numerical index of a family of 33-dimensional polyhedral Banach spaces for the first time, in order to illustrate the applicability of our method.

Keywords

Cite

@article{arxiv.1809.04778,
  title  = {On the numerical index of polyhedral Banach spaces},
  author = {Debmalya Sain and Kallol Paul and Pintu Bhunia and Santanu Bag},
  journal= {arXiv preprint arXiv:1809.04778},
  year   = {2024}
}