English

Sampling projections in the uniform norm

Functional Analysis 2025-10-02 v2 Numerical Analysis Numerical Analysis

Abstract

We show that there are sampling projections on arbitrary nn-dimensional subspaces of B(D)B(D) with at most 2n2n samples and norm of order n\sqrt{n}, where B(D)B(D) is the space of complex-valued bounded functions on a set DD. This gives a more explicit form of the Kadets-Snobar theorem for the uniform norm and improves upon Auerbach's lemma. We discuss consequences for optimal recovery in LpL_p.

Keywords

Cite

@article{arxiv.2401.02220,
  title  = {Sampling projections in the uniform norm},
  author = {David Krieg and Kateryna Pozharska and Mario Ullrich and Tino Ullrich},
  journal= {arXiv preprint arXiv:2401.02220},
  year   = {2025}
}
R2 v1 2026-06-28T14:08:36.480Z