English

The Rational Number Game

Combinatorics 2024-12-23 v2

Abstract

We investigate a game played between two players, Maker and Breaker, on a countably infinite complete graph where the vertices are the rational numbers. The players alternately claim unclaimed edges. It is Maker's goal to have after countably many turns a complete infinite graph contained in her coloured edges where the vertex set of the subgraph is order-isomorphic to the rationals. It is Breaker's goal to prevent Maker from achieving this. We prove that there is a winning strategy for Maker in this game. We also prove that there is a winning strategy for Breaker in the game where Maker must additionally make the vertex set of her complete graph dense in the rational numbers.

Keywords

Cite

@article{arxiv.2309.05526,
  title  = {The Rational Number Game},
  author = {Nathan Bowler and Florian Gut},
  journal= {arXiv preprint arXiv:2309.05526},
  year   = {2024}
}
R2 v1 2026-06-28T12:18:09.821Z