Abstract
It is shown that the set of squares {n 2|n=1, 2,…} or, more generally, sets {n t|n=1, 2,…},t a positive integer, satisfies the pointwise ergodic theorem forL 2-functions. This gives an affirmative answer to a problem considered by A. Bellow [Be] and H. Furstenberg [Fu]. The previous result extends to polynomial sets {p(n)|n=1, 2,…} and systems of commuting transformations. We also state density conditions for random sets of integers in order to be “good sequences” forL p-functions,p>1.
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References
J. Bourgain,Théorèmes ergodiques poncheels pour certains ensembles arithmétiques, C.R. Acad. Sci. Paris305 (1987), 397–402.
J. Bourgain,On the pointwise ergodic theorem on L p for arithmetic sets, Isr. J. Math.61 (1988), 73–84, this issue.
A. Bellow,Two Problems, Lecture Notes in Math.945, Springer-Verlag, Berlin, pp. 429–431.
A. Bellow and V. Losert,On sequences of density zero in ergodic theory, Contemp. Math.26 (1984), 49–60.
H. Furstenberg, Proc. Durham Conf., June 1982.
R. Lidl, H. and Neiderreiter,Finite fields, Encyclopedia of Mathematics and its Applications, 20, Addison-Wesley Publ. Co., 1983.
J. M. Marstrand,On Khinchine’s conjecture about strong uniform distribution, Proc. London Math. Soc.21 (1970), 540–556.
A. Sarközy,On difference sets of sequences of integers, I, Acta Math. Acad. Sci. Hung.31 (1978), 125–149.
E. Stein,Beijing Lectures in Harmonic Analysis, Ann. Math. Studies, Princeton University Press, 1986, p. 112.
R. C. Vaughan,The Hardy-Littlewood Method, Cambridge tracts,80 (1981).
Vinogradov,The Method of Trigonometrical Sums in the Theory of Numbers, Interscience, New York, 1954.
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Bourgain, J. On the maximal ergodic theorem for certain subsets of the integers. Israel J. Math. 61, 39–72 (1988). https://doi.org/10.1007/BF02776301
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DOI: https://doi.org/10.1007/BF02776301