Tytuł artykułu
Autorzy
Wybrane pełne teksty z tego czasopisma
Identyfikatory
Warianty tytułu
Języki publikacji
Abstrakty
Certain properties of Fi-approximants and || || (fi)-approximants were studied by Landers and Rogge, where || || (fi) is the Luxemburg norm. In particular, they investigated the existence of best ||.|| (fi)-approximants and the structure of the . set of best ||.||(fi)-approximants. These authors proved that the set of best ||.||(fi)-approximants of f given a Fi-closed lattice C is a lattice. In this paper we show that this result does not hold if we consider the Orlicz norm in place of the Luxemburg norm. Furthermore, we see that for a large class of functions Fi and measurable spaces the following statements are equivalent: 1) the set of all best || || (fi)-approximants to f in C is a lattice, for every Fi-closed lattice C and f L_fi. 2) (L_fi,,||.||fi) = (L_p,m||.||_p), for some m > 0 and 1 < p < oo.
Wydawca
Rocznik
Tom
Strony
87--102
Opis fizyczny
Bibliogr. 10 poz.
Twórcy
autor
- Universidad Nacional de Rio Cuarto, 5800-Rio Cuarto, Argentina, fmazzone@exa.unrc.edu.ar
Bibliografia
- [1] H. Brunk, Uniform inequalities for conditional p-means given σ-lattices, Ann. Probability 3 (1975), 1025-1030.
- [2] E. W. Cheney, Introduction to Approximation Theory, McGraw Hill, 1966.
- [3] M. Krasnosel’skii and Y. Rutickii, Convex Function and Orlicz Spaces, P. Noordhorff. Ltd, 1961.
- [4] D. Landers and L. Rogge. Best approximants in LΦ-spaces, Z. Wahrsch. Verw. Gabiete 51 (1980), 215-237.
- [5] D. Landers and L. Rogge, Continuity of best approximants, Proc. Am. Math. Soc. 83 (1981), 683-689.
- [6] D. Landers and L. Rogge, A Characterization of best Φ-approximants, Trans. Am. Math. Soc. 267 (1981), 259-264.
- [7] M. Rao and Z. Ren, Theory of Orlicz Spaces, Marcel Dekker, 1991.
- [8] T. Shintani and T. Ando, Best approximants in L1 space, Z. Wahrsch. Verw. Gabiete 33 (1975), 33-39.
- [9] D. Yanzheng and C. Shutao, On best approximation operators in Orlicz spaces, Jour. Math. Anal. Appl. 178 (1993), 1-8.
- [10] S. Kilmer, W. M. Kozłowski and G. Lewicki, Best approximants in modular function spaces, Jour. Approx. Th. 63 (1990), 338-367.
Typ dokumentu
Bibliografia
Identyfikator YADDA
bwmeta1.element.baztech-article-BUS2-0002-0049