English

On the power of adaption and randomization

Numerical Analysis 2025-09-24 v2 Computational Complexity Numerical Analysis Functional Analysis

Abstract

We present bounds on the maximal gain of adaptive and randomized algorithms over non-adaptive, deterministic ones for approximating linear operators on convex sets. If the sets are additionally symmetric, then our results are optimal. For non-symmetric sets, we unify some notions of nn-widths and s-numbers, and show their connection to minimal errors. We also discuss extensions to non-linear widths and approximation based on function values, and conclude with a list of open problems.

Keywords

Cite

@article{arxiv.2406.07108,
  title  = {On the power of adaption and randomization},
  author = {David Krieg and Erich Novak and Mario Ullrich},
  journal= {arXiv preprint arXiv:2406.07108},
  year   = {2025}
}
R2 v1 2026-06-28T17:01:04.346Z