English

$d$-Galvin families

Combinatorics 2019-01-10 v1

Abstract

The Galvin problem asks for the minimum size of a family F([n]n/2)\mathcal{F} \subseteq \binom{[n]}{n/2} with the property that, for any set AA of size n2\frac n 2, there is a set SFS \in \mathcal{F} which is balanced on AA, meaning that SA=SA|S \cap A| = |S \cap \overline{A}|. We consider a generalization of this question that comes from a possible approach in complexity theory. In the generalization the required property is, for any AA, to be able to find dd sets from a family F([n]n/d)\mathcal{F} \subseteq \binom{[n]}{n/d} that form a partition of [n][n] and such that each part is balanced on AA. We construct such families of size polynomial in the parameters nn and dd.

Keywords

Cite

@article{arxiv.1901.02652,
  title  = {$d$-Galvin families},
  author = {Johan Håstad and Guillaume Lagarde and Joseph Swernofsky},
  journal= {arXiv preprint arXiv:1901.02652},
  year   = {2019}
}

Comments

9 pages, 6 figures

R2 v1 2026-06-23T07:06:50.394Z