Abstract
We show that in order for a Walsh series to be locally constant it is necessary for certain blocks of that series to sum to zero. As a consequence, we show that a functionf with a somewhat sparse Walsh—Fourier series is necessarily a Walsh polynomial if its strong dyadic derivative is constant on an interval. In particular, if a Rademacher seriesR is strongly dyadically differentiable and if that derivative is constant on any open subset of [0, 1], thenR is a Rademacher polynomial.
Similar content being viewed by others
References
P. L. Butzer andH. J. Wagner, Walsh—Fourier series and the concept of a derivative,Appl. Analysis 3 (1973), 29–46.Zbl 256. 42016
N. J. Fine, On the Walsh functions,Trans. Amer. Math. Soc. 65 (1949), 372–414.MR 11—352
C. W. Onneweer, Differentiability for Rademacher series on groups,Acta Sci. Math. (Szeged)39 (1977), 121–128.MR 55 # 13149
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wade, W.R. Locally constant dyadic derivatives. Period Math Hung 13, 71–74 (1982). https://doi.org/10.1007/BF01848097
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01848097