Intersection Games and Bernstein Sets
James Atchley, Lior Fishman, Saisneha Ghatti
TL;DR
The paper investigates the determinacy of three classic intersection games on the real line when the target set is a Bernstein set, a non-Lebesgue measurable set constructed via the axiom of choice. By showing that any purported winning strategy would force the target (or its complement) to contain a perfect set, it proves that Bernstein sets cannot host a winning strategy for Banach-Mazur, McMullen's Absolute Winning, or Schmidt's game under the stated parameter regimes. The results illuminate the tension between axiom-of-choice constructions and determinacy, highlighting how Bernstein sets obstruct determinacy even in prominent, dimension-theoretic game scenarios. These insights have implications for understanding the limits of determinacy axioms and the geometric structure of exceptional sets in real analysis.
Abstract
The Banach-Mazur game, Schmidt's game and McMullen's absolute winning game are three quintessential intersection games. We investigate their determinacy on the real line when the target set for either player is a Bernstein set, a non-Lebesgue measurable set whose construction depends on the axiom of choice.
