Czechoslovak Mathematical Journal

, Volume 65, Issue 4, pp 983–1002 | Cite as

On the Nörlund means of Vilenkin-Fourier series

  • István Blahota
  • Lars-Erik Persson
  • Giorgi Tephnadze
Article

Abstract

We prove and discuss some new (H p ,L p )-type inequalities of weighted maximal operators of Vilenkin-Nörlund means with non-increasing coefficients {q k : k ⩾ 0}. These results are the best possible in a special sense. As applications, some well-known as well as new results are pointed out in the theory of strong convergence of such Vilenkin-Nörlund means. To fulfil our main aims we also prove some new estimates of independent interest for the kernels of these summability results.

In the special cases of general Nörlund means t n with non-increasing coefficients analogous results can be obtained for Fejér and Cesàro means by choosing the generating sequence {q k : k ⩾ 0} in an appropriate way.

Keywords

Vilenkin system Vilenkin group Nörlund means martingale Hardy space maximal operator Vilenkin-Fourier series strong convergence inequality 

MSC 2010

42C10 42B25 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    I. Blahota: On a norm inequality with respect to Vilenkin-like systems. Acta Math. Hung. 89 (2000), 15–27.MATHMathSciNetCrossRefGoogle Scholar
  2. [2]
    I. Blahota: Relation between Dirichlet kernels with respect to Vilenkin-like systems. Acta Acad. Paedagog. Agriensis, Sect. Mat. (N. S.) 22 (1994), 109–114.MATHGoogle Scholar
  3. [3]
    I. Blahota, G. Gát: Norm summability of Nörlund logarithmic means on unbounded Vilenkin groups. Anal. Theory Appl. 24 (2008), 1–17.MATHMathSciNetCrossRefGoogle Scholar
  4. [4]
    I. Blahota, G. Tephnadze: On the (C, α)-means with respect to the Walsh system. Anal. Math. 40 (2014), 161–174.MATHMathSciNetCrossRefGoogle Scholar
  5. [5]
    I. Blahota, G. Tephnadze: Strong convergence theorem for Vilenkin-Fejér means. Publ. Math. Debrecen 85 (2014), 181–196.MATHMathSciNetCrossRefGoogle Scholar
  6. [6]
    N. Fujii: A maximal inequality for H 1-functions on a generalized Walsh-Paley group. Proc. Am. Math. Soc. 77 (1979), 111–116.MATHGoogle Scholar
  7. [7]
    G. Gát: Cesàro means of integrable functions with respect to unbounded Vilenkin systems. J. Approx. Theory 124 (2003), 25–43.MATHMathSciNetCrossRefGoogle Scholar
  8. [8]
    G. Gát: Investigations of certain operators with respect to the Vilenkin system. Acta Math. Hung. 61 (1993), 131–149.MATHCrossRefGoogle Scholar
  9. [9]
    G. Gát, U. Goginava: Almost everywhere convergence of (C,α)-means of quadratical partial sums of double Vilenkin-Fourier series. Georgian Math. J. 13 (2006), 447–462.MATHMathSciNetGoogle Scholar
  10. [10]
    G. Gát, U. Goginava: Uniform and L-convergence of logarithmic means of Walsh-Fourier series. Acta Math. Sin., Engl. Ser. 22 (2006), 497–506.MATHMathSciNetCrossRefGoogle Scholar
  11. [11]
    G. Gát, K. Nagy: On the logarithmic summability of Fourier series. Georgian Math. J. 18 (2011), 237–248.MATHMathSciNetGoogle Scholar
  12. [12]
    U. Goginava: Weak type inequality for the maximal operator of the (C, α) means of two-dimensional Walsh-Fourier series. Anal. Math. 36 (2010), 1–31.MATHMathSciNetCrossRefGoogle Scholar
  13. [13]
    U. Goginava: Maximal operators of Fejér-Walsh means. Acta Sci. Math. 74 (2008), 615–624.MATHMathSciNetGoogle Scholar
  14. [14]
    U. Goginava: The maximal operator of Marcinkiewicz-Fejér means of the d-dimensional Walsh-Fourier series. East J. Approx. 12 (2006), 295–302.MathSciNetGoogle Scholar
  15. [15]
    U. Goginava: The maximal operator of the (C, α) means of the Walsh-Fourier series. Ann. Univ. Sci. Budap. Rolando Eötvös, Sect. Comput. 26 (2006), 127–135.MATHMathSciNetGoogle Scholar
  16. [16]
    U. Goginava: Almost everywhere convergence of subsequence of logarithmic means of Walsh-Fourier series. Acta Math. Acad. Paedagog. Nyházi. (N. S.) (electronic only) 21 (2005), 169–175.MATHMathSciNetGoogle Scholar
  17. [17]
    U. Goginava: On the approximation properties of Cesàro means of negative order of Walsh-Fourier series. J. Approx. Theory 115 (2002), 9–20.MATHMathSciNetCrossRefGoogle Scholar
  18. [18]
    C. N. Moore: Summable Series and Convergence Factors. Dover Publications, New York, 1966.MATHGoogle Scholar
  19. [19]
    F. Móricz, A. H. Siddiqi: Approximation by Nörlund means of Walsh-Fourier series. J. Approx. Theory 70 (1992), 375–389.MATHMathSciNetCrossRefGoogle Scholar
  20. [20]
    K. Nagy: Approximation by Nörlund means of double Walsh-Fourier series for Lipschitz functions. Math. Inequal. Appl. 15 (2012), 301–322.MATHMathSciNetGoogle Scholar
  21. [21]
    K. Nagy: Approximation by Nörlund means ofWalsh-Kaczmarz-Fourier series. Georgian Math. J. 18 (2011), 147–162.MATHMathSciNetGoogle Scholar
  22. [22]
    K. Nagy: Approximation by Cesàro means of negative order of Walsh-Kaczmarz-Fourier series. East J. Approx. 16 (2010), 297–311.MATHMathSciNetGoogle Scholar
  23. [23]
    K. Nagy: Approximation by Nörlund means of quadratical partial sums of double Walsh-Fourier series. Anal. Math. 36 (2010), 299–319.MATHMathSciNetCrossRefGoogle Scholar
  24. [24]
    J. Pál, P. Simon: On a generalization of the concept of derivative. Acta Math. Acad. Sci. Hung. 29 (1977), 155–164.MATHCrossRefGoogle Scholar
  25. [25]
    F. Schipp: Rearrangements of series in the Walsh system. Math. Notes 18 (1976), 701–706; translation from Mat. Zametki 18 (1975), 193–201.MATHCrossRefGoogle Scholar
  26. [26]
    P. Simon: Cesàro summability with respect to two-parameter Walsh systems. Monatsh. Math. 131 (2000), 321–334.MathSciNetCrossRefGoogle Scholar
  27. [27]
    P. Simon: Strong convergence theorem for Vilenkin-Fourier series. J. Math. Anal. Appl. 245 (2000), 52–68.MATHMathSciNetCrossRefGoogle Scholar
  28. [28]
    P. Simon: Investigations with respect to the Vilenkin system. Ann. Univ. Sci. Budap. Rolando Eötvös, Sect. Math. 27 (1984), 87–101.MATHGoogle Scholar
  29. [29]
    P. Simon, F. Weisz: Weak inequalities for Cesàro and Riesz summability of Walsh-Fourier series. J. Approx. Theory 151 (2008), 1–19.MATHMathSciNetCrossRefGoogle Scholar
  30. [30]
    G. Tephnadze: On the maximal operators of Riesz logarithmic means of Vilenkin-Fourier series. Stud. Sci. Math. Hung. 51 (2014), 105–120.MATHMathSciNetGoogle Scholar
  31. [31]
    G. Tephnadze: On the partial sums of Vilenkin-Fourier series. J. Contemp. Math. Anal. 49 (2014), 23–32. (In Russian.)MathSciNetCrossRefGoogle Scholar
  32. [32]
    G. Tephnadze: Strong convergence theorems for Walsh-Fejér means. Acta Math. Hung. 142 (2014), 244–259.MATHMathSciNetCrossRefGoogle Scholar
  33. [33]
    G. Tephnadze: On the maximal operators of Vilenkin-Fejér means on Hardy spaces. Math. Inequal. Appl. 16 (2013), 301–312.MATHMathSciNetGoogle Scholar
  34. [34]
    G. Tephnadze: On the maximal operators of Vilenkin-Fejér means. Turk. J. Math. 37 (2013), 308–318.MATHMathSciNetGoogle Scholar
  35. [35]
    G. Tephnadze: A note on the Fourier coefficients and partial sums of Vilenkin-Fourier series. Acta Math. Acad. Paedagog. Nyházi. (N. S.) (electronic only) 28 (2012), 167–176.MATHMathSciNetGoogle Scholar
  36. [36]
    G. Tephnadze: Fejér means of Vilenkin-Fourier series. Stud. Sci. Math. Hung. 49 (2012), 79–90.MATHMathSciNetGoogle Scholar
  37. [37]
    G. Tephnadze: The maximal operators of logarithmic means of one-dimensional Vilenkin-Fourier series. Acta Math. Acad. Paedagog. Nyházi. (N. S.) (electronic only) 27 (2011), 245–256.MATHMathSciNetGoogle Scholar
  38. [38]
    N. J. Vilenkin: On a class of complete orthonormal systems. Am. Math. Soc. Transl. Ser. (2), 28 (1963), 1–35; translation from Izv. Akad. Nauk SSSR, Ser. Mat. 11 (1947), 363–400.MATHMathSciNetGoogle Scholar
  39. [39]
    F. Weisz: θ-summability of Fourier series. Acta Math. Hung. 103 (2004), 139–176.MATHMathSciNetCrossRefGoogle Scholar
  40. [40]
    F. Weisz: (C, α) summability of Walsh-Fourier series. Anal. Math. 27 (2001), 141–155.MATHMathSciNetCrossRefGoogle Scholar
  41. [41]
    F. Weisz: Cesàro summability of one- and two-dimensional Walsh-Fourier series. Anal. Math. 22 (1996), 229–242.MATHMathSciNetCrossRefGoogle Scholar
  42. [42]
    F. Weisz: Martingale Hardy Spaces and Their Applications in Fourier Analysis. Lecture Notes in Mathematics 1568, Springer, Berlin, 1994.MATHGoogle Scholar

Copyright information

© Institute of Mathematics of the Academy of Sciences of the Czech Republic, Praha, Czech Republic 2015

Authors and Affiliations

  • István Blahota
    • 1
  • Lars-Erik Persson
    • 2
    • 3
  • Giorgi Tephnadze
    • 4
    • 2
  1. 1.Institute of Mathematics and Computer SciencesCollege of NyíregyházaNyíregyházaHungary
  2. 2.Department Of Engineering Sciences and MathematicsLuleå University of TechnologyLuleåSweden
  3. 3.Narvik University CollegeNarvikNorway
  4. 4.Department of Mathematics, Faculty of Exact and Natural SciencesTbilisi State UniversityTbilisiGeorgia

Personalised recommendations