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A group version of stable regularity. (English) Zbl 1539.03116

Summary: We prove that, given \(\epsilon > 0\) and \(k \geq 1\), there is an integer \(n\) such that the following holds. Suppose \(G\) is a finite group and \(A \subseteq G\) is \(k\)-stable. Then there is a normal subgroup \(H \leq G\) of index at most \(n\), and a set \(Y \subseteq G\), which is a union of cosets of \(H\), such that \(|A \triangle Y| \leq \epsilon |H|\). It follows that, for any coset \(C\) of \(H\), either \(|C \cap A|\leq \epsilon|H|\) or \(|C A| \leq \epsilon |H|\). This qualitatively generalises recent work of Terry and Wolf on vector spaces over \(\mathbb{F}_p\).

MSC:

03C45 Classification theory, stability, and related concepts in model theory
03C60 Model-theoretic algebra
20A15 Applications of logic to group theory

References:

[1] Green, B.A Szemerédi-type regularity lemma in abelian groups, with applications. Geom. Funct. Anal.15 (2005), no. 2, 340-376. · Zbl 1160.11314
[2] Hrushovski, E.Pseudo-finite fields and related structures, Model theory and applications. Quad. Mat. vol. 11 (Aracne, Rome, 2002), pp. 151-212. · Zbl 1082.03035
[3] Hrushovski, E.Stable group theory and approximate subgroups. J. Amer. Math. Soc.25 (2012), no. 1, 189-243. · Zbl 1259.03049
[4] Hrushovski, E., Peterzil, Y. and Pillay, A.Groups, measures, and the NIP. J. Amer. Math. Soc.21 (2008), no. 2, 563-596. · Zbl 1134.03024
[5] Hrushovski, E. and Pillay, A.Groups definable in local fields and pseudo-finite fields. Israel J. Math.85 (1994), no. 1-3, 203-262. · Zbl 0804.03024
[6] Malliaris, M. and Pillay, A.The stable regularity lemma revisited. Proc. Amer. Math. Soc.144 (2016), no. 4, 1761-1765. · Zbl 1348.03033
[7] Malliaris, M. and Shelah, S.Regularity lemmas for stable graphs. Trans. Amer. Math. Soc.366 (2014), no. 3, 1551-1585. · Zbl 1283.05234
[8] Newelski, L. and Petrykowski, M.Weak generic types and coverings of groups. I. Fund. Math.191 (2006), no. 3, 201-225. · Zbl 1111.03036
[9] Pillay, A. Geometric stability theory. Oxford Logic Guides, vol. 32. (The Clarendon Press, Oxford University Press, New York, 1996, Oxford Science Publications). · Zbl 0871.03023
[10] Shelah, S. Classification theory and the number of nonisomorphic models, second ed. Studies in Logic and the Foundations of Mathematics, vol. 92 (North-Holland Publishing Co., Amsterdam, 1990). · Zbl 0713.03013
[11] Terry, C. and Wolf, J.. Stable arithmetic regularity in the finite-field model. arXiv:1710.02021 (2017). · Zbl 1462.11015
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