English

Controlling cardinal characteristics without adding reals

Logic 2021-05-18 v2

Abstract

We investigate the behavior of cardinal characteristics of the reals under extensions that do not add new <κ{<}\kappa-sequences (for some regular κ\kappa). As an application, we show that consistently the following cardinal characteristics can be different: The ("independent") characteristics in Cicho\'n's diagram, plus 1<m<p<h<add(N)\aleph_1<\mathfrak m<\mathfrak p<\mathfrak h<\mathrm{add}(\mathcal{N}). (So we get thirteen different values, including 1\aleph_1 and continuum). We also give constructions to alternatively separate other MA-numbers (instead of m\mathfrak m), namely: MA for kk-Knaster from MA for k+1k+1-Knaster; and MA for the union of all kk-Knaster forcings from MA for precaliber.

Cite

@article{arxiv.2006.09826,
  title  = {Controlling cardinal characteristics without adding reals},
  author = {Martin Goldstern and Jakob Kellner and Diego A. Mejía and Saharon Shelah},
  journal= {arXiv preprint arXiv:2006.09826},
  year   = {2021}
}

Comments

This is a variant of arXiv:1904.02617 which does not require large cardinals, as it it based on arXiv:1906.06608 instead of arXiv:1708.03691

R2 v1 2026-06-23T16:24:09.692Z