Abstract
We prove the convergence inL 1([−gp, π)2)-norm of the double Fourier series of an integrable functionf(x, y) which is periodic and even with respect tox andy, with coefficientsa jk satisfying certain conditions of Hardy-Karamata kind, and such thata jk logj logk→0 asj, k→∞. These sufficient conditions become quite natural in particular cases. Then we extend these results to the convergence of double Walsh-Fourier series inL 1 (0, 1)2)- norm. As a by-product, we obtain Tauberian conditions ensuring the convergence of a double numerical series provided it is Cesàro summable.
Similar content being viewed by others
References
R. Bojanic and Č. V. Stanojević,A class of L 1-convergence, Trans. Amer. Math. Soc.269 (1982), 677–683.
W. O. Bray and Č. V. Stanojević,Tauberian L 1-convergence class of Fourier series II, Math. Ann.269(1984), 469–486.
Chen Chang-Pao,L 1-convergence of Fourier series, J. Austral. Math. Soc. (Series A)41(1986), 376–390.
N. J. Fine,On Walsh functions, Trans. Amer. Math. Soc.65(1949), 372–414.
J. W. Garrett and Č. V. Stanojević,On L 1-convergence of certain cosine series, Proc. Amer. Math. Soc.54(1976), 101–105.
G. Morgenthaler,Walsh-Fourier series, Trans. Amer. Math. Soc.84(1957), 472–507.
F. Móricz,On L 1-convergence of Walsh-Fourier series I, Rendiconti Circ. Mat. Palermo (Serie II)38(1989), 411–418.
F. Móricz,Integrability and L 1-convergence of double trigonometric series, Studia Math.98(1991), 203–225.
F. Móricz and F. Schipp,On the integrability and L 1-convergence of Walsh series with coefficients of bounded variation, J. Math. Anal. Appl.146(1990), 99–109.
F. Móricz and F. Schipp,On the integrability and L 1-convergence of double Walsh series, Acta Math. Hungar.57(1991), 371–380.
R. E. A. C. Paley,A remarkable system of orthogonal functions, Proc. London Math. Soc.34(1932), 241–279.
F. Schipp, W. R. Wade and P. Simon,Walsh Series. An Introduction to Dyadic Harmonic Analysis, Akadémiai Kiadó, Budapest, 1990.
A. Zygmund,Trigonometric Series, Cambridge University Press, 1959.
Author information
Authors and Affiliations
Additional information
This research was partially supported by the Hungarian National Foundation for Scientific Research under Grant # 234.
Rights and permissions
About this article
Cite this article
Móricz, F. L 1-convergence of double cosine- and Walsh-Fourier series. J. Anal. Math. 62, 115–130 (1994). https://doi.org/10.1007/BF02835950
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02835950