English

On the Rudin-Blass Ordering of Measures

Logic 2026-02-06 v2 Classical Analysis and ODEs

Abstract

We study the Rudin-Blass (and the Rudin-Keisler) ordering on the finite additive measures on ω\omega. We propose a generalization of the notion of Q-point and selective ultrafilter to measures: Q-measures and selective measures. We show some symmetries between Q-points and Q-measures but also we show where those symmetries break up. In particular we present an example of a measure which is minimal in the sense of Rudin-Blass but which is not a Q-measure.

Keywords

Cite

@article{arxiv.2504.14678,
  title  = {On the Rudin-Blass Ordering of Measures},
  author = {Piotr Borodulin-Nadzieja and Arturo Martínez-Celis and Adam Morawski and Jadwiga Świerczyńska},
  journal= {arXiv preprint arXiv:2504.14678},
  year   = {2026}
}

Comments

35 pages