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Multiple recurrence and convergence for hardy sequences of polynomial growth

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Abstract

We study the limiting behavior of multiple ergodic averages involving sequences of integers that satisfy some regularity conditions and have polynomial growth. We show that for “typical” choices of Hardy field functions a(t) with polynomial growth, the averages

$${1 \over N}\sum\nolimits_{n = 1}^N {{f_1}({T^{[a(n)]}}x) \cdots {f_\ell }({T^{\ell [a(n)]}}x)} $$

converge in mean and we determine their limit. For example, this is the case if a(t) = t 3/2, t log t, or t 2 + (log t)2. Furthermore, if {a 1(t), …, a (t)} is a “typical” family of logarithmico-exponential functions of polynomial growth, then for every ergodic system, the averages

$${1 \over N}\sum\nolimits_{n = 1}^N {{f_1}({T^{[{a_1}(n)]}}x) \cdots {f_\ell }({T^{[{a_\ell }(n)]}}x)} $$

converge in mean to the product of the integrals of the corresponding functions. For example, this is the case if the functions a i (t) are given by different positive fractional powers of t. We deduce several results in combinatorics. We show that if a(t) is a non-polynomial Hardy field function with polynomial growth, then every set of integers with positive upper density contains arithmetic progressions of the form {m,m + [a(n)], …, m + [a(n)]}. Under suitable assumptions, we get a related result concerning patterns of the form {m,m + [a 1(n)], …,m + [a (n)]}.

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References

  1. T. Austin, On the norm convergence on nonconventional ergodic averages, Ergodic Theory Dynam. Systems 30 (2010), 321–338.

    Article  MATH  MathSciNet  Google Scholar 

  2. D. Berend, Joint ergodicity and mixing, J. Analyse Math. 45 (1985), 255–284.

    Article  MATH  MathSciNet  Google Scholar 

  3. V. Bergelson, Weakly mixing PET, Ergodic Theory Dynam. Systems 7 (1987), 337–349.

    Article  MATH  MathSciNet  Google Scholar 

  4. V. Bergelson, Ergodic Ramsey Theory, in Logic and Combinatorics, Amer. Math. Soc., Providence RI, 1987, pp. 63–87.

    Google Scholar 

  5. V. Bergelson, M. Boshernitzan and J. Bourgain, Some results on nonlinear recurrence, J. Analyse Math. 62 (1994), 29–46.

    Article  MATH  MathSciNet  Google Scholar 

  6. V. Bergelson and I. Håland, Sets of recurrence and generalized polynomials, in Convergence in Ergodic Theory and Probability (Columbus, OH, 1993), de Gruyter, Berlin, 1996, pp. 91–110.

    Google Scholar 

  7. V. Bergelson and I. Håland-Knutson, Weak mixing implies mixing of higher orders along tempered functions, Ergodic Theory Dynam. Systems 29 (2009), 1375–1416.

    Article  MATH  MathSciNet  Google Scholar 

  8. V. Bergelson, B. Host, R. McCutcheon and F. Parreau, Aspects of uniformity in recurrence, Colloq. Math. 84/85 (2000), 549–576.

    MathSciNet  Google Scholar 

  9. V. Bergelson and A. Leibman, Polynomial extensions of van der Waerden’s and Szemerédi’s theorems, J. Amer. Math. Soc. 9 (1996), 725–753.

    Article  MATH  MathSciNet  Google Scholar 

  10. V. Bergelson, A. Leibman and E. Lesigne, Intersective polynomials and polynomial Szemeredi theorem, Adv. Math. 219 (2008), 369–388.

    Article  MATH  MathSciNet  Google Scholar 

  11. M. Boshernitzan, Uniform distribution and Hardy fields, J. Analyse Math. 62 (1994), 225–240.

    Article  MATH  MathSciNet  Google Scholar 

  12. M. Boshernitzan, G. Kolesnik, A. Quas and M. Wierdl, Ergodic averaging sequences, J. Analyse. Math. 95 (2005), 63–103.

    Article  MATH  MathSciNet  Google Scholar 

  13. N. Frantzikinakis, Multiple ergodic averages for three polynomials and applications, Trans. Amer. Math. Soc. 360 (2008), 5435–5475.

    Article  MATH  MathSciNet  Google Scholar 

  14. N. Frantzikinakis, Equidistribution of sparse sequences on nilmanifolds, J. Analyse Math. 109 (2009), 1–49.

    Article  MathSciNet  Google Scholar 

  15. N. Frantzikinakis, B. Host and B. Kra, Multiple recurrence and convergence for sets related to the primes, J. Reine Angew. Math. 611 (2007), 131–144.

    MATH  MathSciNet  Google Scholar 

  16. N. Frantzikinakis and B. Kra, Ergodic averages for independent polynomials and applications, J. London Math. Soc. (2) 74 (2006), 131–142.

    Article  MATH  MathSciNet  Google Scholar 

  17. N. Frantzikinakis and M. Wierdl, A Hardy field extension of Szemerédi’s theorem, Adv. in Math. 222 (2009), 1–43.

    Article  MATH  MathSciNet  Google Scholar 

  18. H. Furstenberg, Ergodic behavior of diagonalmeasures and a theorem of Szemerédi on arithmetic progressions, J. Analyse Math. 71 (1977), 204–256.

    Article  MathSciNet  Google Scholar 

  19. H. Furstenberg, Recurrence in Ergodic Theory and Combinatorial Number Theory, Princeton University Press, Princeton, 1981.

    MATH  Google Scholar 

  20. H. Furstenberg and Y. Katznelson, An ergodic Szemerédi theorem for commuting transformations, J. Analyse Math. 34 (1979), 275–291.

    Article  MathSciNet  Google Scholar 

  21. B. Green and T. Tao, The primes contain arbitrarily long arithmetic progressions, Ann. of Math. (2) 167 (2008), 481–547.

    Article  MATH  MathSciNet  Google Scholar 

  22. B. Green and T. Tao, The quantitative behaviour of polynomial orbits on nilmanifolds, Preprint, 2007. Available at arXiv:0709.3562

  23. G. Hardy, Properties of logarithmico-exponential functions, Proc. London Math. Soc. (2) 10 (1912), 54–90.

    Article  Google Scholar 

  24. G. Hardy, Orders of Infinity, 2nd edition, Cambridge University Press, Cambridge, 1924.

    MATH  Google Scholar 

  25. B. Host, Ergodic seminorms for commuting transformations and applications, Preprint, 2008. Available at arXiv:0811.3703

  26. B. Host and B. Kra, Nonconventional ergodic averages and nilmanifolds, Ann. of Math. (2) 161 (2005), 397–488.

    Article  MATH  MathSciNet  Google Scholar 

  27. B. Host and B. Kra, Convergence of polynomial ergodic averages, Israel J. Math. 149 (2005), 1–19.

    Article  MATH  MathSciNet  Google Scholar 

  28. A. Leibman, Pointwise convergence of ergodic averages for polynomial sequences of rotations of a nilmanifold, Ergodic Theory Dynam. Systems 25 (2005), 201–213.

    Article  MATH  MathSciNet  Google Scholar 

  29. A. Leibman, Convergence of multiple ergodic averages along polynomials of several variables, Israel J. Math. 146 (2005), 303–316.

    Article  MATH  MathSciNet  Google Scholar 

  30. A. Leibman, Orbit of the diagonal in the power of a nilmanifold, Trans. Amer. Math. Soc. 362 (2010), 1619–1658.

    Article  MATH  MathSciNet  Google Scholar 

  31. K. Petersen, Ergodic Theory, Cambridge Studies in Advanced Mathematics, 2. Cambridge University Press, Cambridge, 1989.

    MATH  Google Scholar 

  32. E. Szemerédi, On sets of integers containing no k elements in arithmetic progression, Acta Arith. 27 (1975), 299–345.

    Google Scholar 

  33. T. Tao, Norm convergence of multiple ergodic averages for commuting transformations, Ergodic Theory Dynam. Systems 28 (2008), 657–688.

    Article  MATH  MathSciNet  Google Scholar 

  34. T. Tao and T. Ziegler, The primes contain arbitrarily long polynomial progressions, Acta Math. 201 (2008), 213–305.

    Article  MATH  MathSciNet  Google Scholar 

  35. H. Towsner, Convergence of diagonal ergodic averages, Ergodic Theory Dynam. Systems 29 (2009), 1309–1326.

    Article  MATH  MathSciNet  Google Scholar 

  36. P. Walters, An Introduction to Ergodic Theory, Springer-Verlag, New York-Berlin, 1982.

    MATH  Google Scholar 

  37. T. Ziegler, A non-conventional ergodic theorem for a nilsystem, Ergodic Theory Dynam. Systems 25 (2005), 1357–1370.

    Article  MATH  MathSciNet  Google Scholar 

  38. T. Ziegler, Universal characteristic factors and Furstenberg averages, J. Amer. Math. Soc. 20 (2007), 53–97.

    Article  MATH  MathSciNet  Google Scholar 

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Correspondence to Nikos Frantzikinakis.

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The author was partially supported by NSF grant DMS-0701027 and Marie Curie International Reintegration Grant 248008.

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Frantzikinakis, N. Multiple recurrence and convergence for hardy sequences of polynomial growth. JAMA 112, 79–135 (2010). https://doi.org/10.1007/s11854-010-0026-z

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