English

Steinhaus' lattice-point problem for Banach spaces

Functional Analysis 2016-10-26 v5

Abstract

Steinhaus proved that given a~positive integer nn, one may find a circle surrounding exactly nn points of the integer lattice. This statement has been recently extended to Hilbert spaces by Zwole\'{n}ski, who replaced the integer lattice by any infinite set that intersects every ball in at most finitely many points. We investigate Banach spaces satisfying this property, which we call (S), and characterise them by means of a new geometric property of the unit sphere which allows us to show, e.g., that all strictly convex norms have (S), nonetheless, there are plenty of non-strictly convex norms satisfying (S). We also study the corresponding renorming problem.

Keywords

Cite

@article{arxiv.1302.6443,
  title  = {Steinhaus' lattice-point problem for Banach spaces},
  author = {Tomasz Kania and Tomasz Kochanek},
  journal= {arXiv preprint arXiv:1302.6443},
  year   = {2016}
}

Comments

Accepted for publication in Journal of Mathematical Analysis and Applications

R2 v1 2026-06-21T23:32:50.667Z