Abstract
We consider generalizations of the pointwise and mean ergodic theorems to ergodic theorems averaging along different subsequences of the integers or real numbers. The Birkhoff and Von Neumann ergodic theorems give conclusions about convergence of average measurements of systems when the measurements are made at integer times. We consider the case when the measurements are made at timesa(n) or ([a(n)]) where the functiona(x) is taken from a class of functions called a Hardy field, and we also assume that |a(x)| goes to infinity more slowly than some positive power ofx. A special, well-known Hardy field is Hardy’s class of logarithmico-exponential functions.
The main theme of the paper is to point out that for a functiona(x) as described above, a complete characterization of the ergodic averaging behavior of the sequence ([a(n)]) is possible in terms of the distance ofa(x) from (certain) polynomials.
Similar content being viewed by others
References
M. Boshernitzan,An extension of Hardy’s class of ‘orders of infinity’, J. Analyse Math.39 (1981), 235–255.
M. Boshernitzan,New ‘orders of infinity’, J. Analyse Math.41 (1981), 130–167.
M. Boshernitzan,Uniform distribution and Hardy fields, J. Analyse Math.62 (1994), 225–240.
M. Boshernitzan, R. L. Jones and M. Wierdl,Integer and fractional parts of good averging sequences in ergodic theory, inConvergence in Ergodic Theory and Probability (Columbus, OH, 1993) (V. Bergelson, P. March and J. Rosenblatt, eds.), de Gruyter, Berlin, 1996, pp. 117–132.
M. Boshernitzan and M. Wierdl,Ergodic theorems along sequences and Hardy fields, Proc. Nat. Acad. Sci. U.S.A.93 (1996), no. 16, 8205–8207.
J. Bourgain,Point-wise ergodic theorems for arithmetic sets (appendix: The return time theorem), Publ. Math. I.H.E.S.69 (1989), 5–45.
S. D. Cohen,The distribution of polynomials over finite fields, Acta Arith.17 (1970), 255–271.
J. M. Deshouillers,Problème de Waring avec exposants non entiers, Bull. Soc. Math. France101 (1973), 285–295.
G. H. Hardy,Orders of Infinity, 2nd edn., Cambridge Univ. Press, Cambridge, 1924.
R. Jones and M. Wierdl,Covergence and divergences of ergodic averages, Ergodic Theory Dynam. Systems14 (1994), 515–535.
A. Karatsuba,Basic Analytic Number Theory, Springer-Verlag, Berlin, 1993.
M. Lacey,On an inequality due to Bourgain, Illinois J. Math.41 (1997), 231–236.
E. Lesigne,On the sequence of integer parts of a good sequence for the ergodic theorem, Comment. Math. Univ. Carolin.36 (1995), 737–743.
H. Niederreiter,On a paper of Blum, Eisenberg, and Hahn concerning ergodic theory and the distribution of sequences in the Bohr group, Acta Sci. Math. (Szeged)37 (1975), 103–108.
H. Niederreiter and R. Lidl,Finite Fields, Cambridge Univ. Press, Cambridge, 1983.
J. Rosenblatt and M. Wierdl,Cointwise ergodic theorems via harmonic analysis, inErgodic Theory and its Connections with Harmonic Analysis (K. Petersen and I. Salama, eds.), London Mathematical Society Lecture Note Series, no. 205, Cambridge Univ. Press, 1995, pp. 5–151.
S. Sawyer,Maximal inequalities of weak type, Ann. of Math.84 (1966), 157–174.
J.-P. Thouvenot,La convergence presque sûre des moyennes ergodiques suivant certaines soussuites d'entiers (d'après Jean Bourgain), Astérisque (1990), no. 189-190, Exp. No. 719, 133–153, Séminaire Bourbaki, Vol. 1989/90.
V. Bergelson, M. Boshernitzan and J. Bourgain,Some results on non-linear recurrence, J. Analyse Math.62 (1994), 29–46.
J. G. Van der Corput,Neue zahlentheoretische Abschatzungen II, Math. Z.29 (1929), 397–426.
R. C. Vaughan,The Hardy-Littlewood Method, Cambridge Univ. Press, Cambridge, 1981.
Author information
Authors and Affiliations
Corresponding author
Additional information
This research was supported by grants from the NSF.
Rights and permissions
About this article
Cite this article
Boshernitzan, M., Kolesnik, G., Quas, A. et al. Ergodic averaging sequences. J. Anal. Math. 95, 63–103 (2005). https://doi.org/10.1007/BF02791497
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02791497