English

Nonhomogeneous analytic families of trees

Logic 2008-08-12 v3 Combinatorics

Abstract

We consider a dichotomy for analytic families of trees stating that either there is a colouring of the nodes for which all but finitely many levels of every tree are nonhomogeneous, or else the family contains an uncountable antichain. This dichotomy implies that every nontrivial Souslin poset satisfying the countable chain condition adds a splitting real. We then reduce the dichotomy to a conjecture of Sperner Theory. This conjecture is concerning the asymptotic behaviour of the product of the sizes of the m-shades of pairs of cross-t-intersecting families.

Keywords

Cite

@article{arxiv.0807.0147,
  title  = {Nonhomogeneous analytic families of trees},
  author = {James Hirschorn},
  journal= {arXiv preprint arXiv:0807.0147},
  year   = {2008}
}

Comments

21 pages. v2: Major rewrite, because conjecture 1 of v1 was proved false in arXiv:0808.1434v1. v3: a couple typos Article Homepage: http://homepage.univie.ac.at/James.Hirschorn/research/analytic.dichotomy/analytic.dichotomy.html

R2 v1 2026-06-21T10:56:24.385Z