Abstract
We consider the approximation of periodic functions by trigonometric polynomials in metric (not normed) spaces that are generalizations of the spaces L p , 0 < p < 1, and L 0. In particular, we prove the multidimensional Jackson theorem in L p (Tm), 0 < p < 1.
Similar content being viewed by others
References
D. Jackson, über die Genauigkeit der Anndherung stetiger Functionen durch gauze rationale Functionen gegebenen Grades undtrigonometrische Summen gegebener Ordnung, Dissertation, Gottingen f 1911).
E. Quade, “Trigonometric approximation in the mean,” Duke Math. J., 3, 37–49 (1937).
A. F. Timan, Theory of Approximation of Functions of a Real Variables [in Russian], Fi/matgiz, Moscow (1960).
N. P. Korneichuk, Exact Constants in Approximation Theory [in Russian] Nauka, Moscow 1987.
S. M. Nikol’skii, Approximation of Functions of Many Variables and Imbedding Theorems [in Russian] Nauka, Moscow 1969.
V. A. Yudin, “Multidimensional Jackson theorem,” Mat. Zametki. 20, No. 3, 439–444 (1976).
V. N. Temlyakov, “On approximation of functions of many variables by trigonometric polynomials with harmonics from hyperboliccrosses,” Ukr. Mat. Zh., 41, No. 4, 518–524 (1989).
E. A. Storozhenko, P. Osval’d, and V. G. Krotov, “Direct and inverse theorems of the Jackson type in the spaces L p , 0 < p < 1,” Mat. Sb., 98, No. 3, 395–115 (1975).
V. I. Ivanov, “Direct and inverse theorems of approximation theory in the metric of L p for 0 < p < 1,” Mat. Zametki, 16, No. 5, 641–658 (1975).
A. A. Kornicnko, “On the Jackson theorem in the space with convergence in measure,” E. J. Approxim., 4, No. 1, 15–24 (1998).
K. V. Runovskii, “On approximation by families of linear polynomial operators in the spaces L p , 0 < p < 1,” Mat. Sb., 185, No. 8, 81–102 (1994).
E. Stein and G. Weiss, Introduction to Fourier Analysis on Euclidean Spaces, Princeton University Press, Princeton 1971.
Rights and permissions
About this article
Cite this article
Pichugov, S.A. On the jackson theorem for periodic functions in spaces with integral metric. Ukr Math J 52, 133–147 (2000). https://doi.org/10.1007/BF02514142
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02514142