English

Perturbing PLA

Classical Analysis and ODEs 2012-02-27 v1

Abstract

We proved earlier that every measurable function on the circle, after a uniformly small perturbation, can be written as a power series (i.e. a series of exponentials with positive frequencies), which converges almost everywhere. Here we show that this result is basically sharp: the perturbation cannot be made smooth or even H\"older. We discuss also a similar problem for perturbations with lacunary spectrum.

Keywords

Cite

@article{arxiv.1202.5538,
  title  = {Perturbing PLA},
  author = {Gady Kozma and Alexander Olevskii},
  journal= {arXiv preprint arXiv:1202.5538},
  year   = {2012}
}

Comments

21 pages

R2 v1 2026-06-21T20:24:45.565Z