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DETERMINACY OF SCHMIDT’S GAME AND OTHER INTERSECTION GAMES

Published online by Cambridge University Press:  30 May 2022

LOGAN CRONE
Affiliation:
DEPARTMENT OF MATHEMATICS UNIVERSITY OF NORTH TEXAS 1155 UNION CIRCLE #311430 DENTON TX 76203-5017, USA E-mail: lcronest@gmail.com E-mail: lior.fishman@unt.edu
LIOR FISHMAN
Affiliation:
DEPARTMENT OF MATHEMATICS UNIVERSITY OF NORTH TEXAS 1155 UNION CIRCLE #311430 DENTON TX 76203-5017, USA E-mail: lcronest@gmail.com E-mail: lior.fishman@unt.edu
STEPHEN JACKSON*
Affiliation:
DEPARTMENT OF MATHEMATICS UNIVERSITY OF NORTH TEXAS 1155 UNION CIRCLE #311430 DENTON TX 76203-5017, USA E-mail: lcronest@gmail.com E-mail: lior.fishman@unt.edu
*

Abstract

Schmidt’s game and other similar intersection games have played an important role in recent years in applications to number theory, dynamics, and Diophantine approximation theory. These games are real games, that is, games in which the players make moves from a complete separable metric space. The determinacy of these games trivially follows from the axiom of determinacy for real games, $\mathsf {AD}_{\mathbb R}$ , which is a much stronger axiom than that asserting all integer games are determined, $\mathsf {AD}$ . One of our main results is a general theorem which under the hypothesis $\mathsf {AD}$ implies the determinacy of intersection games which have a property allowing strategies to be simplified. In particular, we show that Schmidt’s $(\alpha ,\beta ,\rho )$ game on $\mathbb R$ is determined from $\mathsf {AD}$ alone, but on $\mathbb R^n$ for $n \geq 3$ we show that $\mathsf {AD}$ does not imply the determinacy of this game. We then give an application of simple strategies and prove that the winning player in Schmidt’s $(\alpha , \beta , \rho )$ game on $\mathbb {R}$ has a winning positional strategy, without appealing to the axiom of choice. We also prove several other results specifically related to the determinacy of Schmidt’s game. These results highlight the obstacles in obtaining the determinacy of Schmidt’s game from $\mathsf {AD}$ .

Type
Article
Copyright
© The Author(s), 2022. Published by Cambridge University Press on behalf of The Association for Symbolic Logic

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References

Akhunzhanov, R. K., On the distribution modulo 1 of exponential sequences . Mathematical Notes , vol. 76 (2004), no. 2, pp. 153160.CrossRefGoogle Scholar
Becker, H. S., Determinacy of Banach games, this Journal, vol. 50 (1985), no. 1, pp. 110–122.Google Scholar
Freiling, C. F., Banach games, this Journal, vol. 49 (1984), no. 2, pp. 343–375.Google Scholar
Kechris, A. S., A coding theorem for measures , Cabal Seminar 81–85 (Kechris, A. S., Martin, D. A., and Steel, J. R., editors), Lecture Notes in Mathematics, vol. 1333, Springer, Berlin, 1987, pp. 103109.CrossRefGoogle Scholar
Kechris, A. S., Classical Descriptive Set Theory , Graduate Texts in Mathematics, vol. 156, Springer, New York, 1995.CrossRefGoogle Scholar
Martin, D. A., A purely inductive proof of Borel determinacy , Recursion Theory (Ithaca, NY, 1982) (Nerode, A. and Shore, R. A., editors), Proceedings of Symposia in Pure Mathematics, vol. 42, American Mathematical Society, Providence, RI, 1985, pp. 303308.CrossRefGoogle Scholar
Martin, D. A., Countable length games , Large Cardinals, Determinacy, and Other Topics: The Cabal Seminar Volume IV (Kechris, A. S., Löwe, B., and Steel, J. R., editors), Cambridge University Press, Cambridge, 2020.Google Scholar
Martin, D. A. and Steel, J. R., The extent of scales in L(), Cabal Seminar 79–81 (Kechris, A. S., Martin, D. A., and Moschovakis, Y. N., editors), Lecture Notes in Mathematics, vol. 1019, Springer, Berlin, 1983, pp. 8696.CrossRefGoogle Scholar
Martin, D. A. and Woodin, H. W., Weakly homogeneous trees , Games, Scales, and Suslin Cardinals: The Cabal Seminar, vol. I (Kechris, A. S., Löwe, B., and Steel, J. R., editors), Lecture Notes in Logic, vol. 31, Cambridge University Press, Cambridge, 2008, pp. 421438.CrossRefGoogle Scholar
McMullen, C. T., Winning sets, quasiconformal maps and Diophantine approximation . Geometric and Functional Analysis , vol. 20 (2010), no. 3, pp. 726740.CrossRefGoogle Scholar
Moschovakis, Y. N., Ordinal games and playful models , Cabal Seminar 77–79 (Kechris, A. S., Martin, D. A., and Moschovakis, Y. N., editors), Lecture Notes in Mathematics, vol. 839, Springer, Berlin, 1981, pp. 169201.CrossRefGoogle Scholar
Moschovakis, Y. N., Descriptive Set Theory , second ed., Mathematical Surveys and Monographs, vol. 155, American Mathematical Society, Providence, RI, 2009.CrossRefGoogle Scholar
Schmidt, W. M., On badly approximable numbers and certain games . Transactions of the American Mathematical Society , vol. 123 (1966), pp. 2750.Google Scholar
Solovay, R. M., The independence of DC from AD , Cabal Seminar 76–77 (Kechris, A. S. and Moschovakis, Y. N., editors), Lecture Notes in Mathematics, vol. 689, Springer, Berlin, 1978, pp. 171183.CrossRefGoogle Scholar