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On (V*) sets and Pelczynski's property (V*)

Published online by Cambridge University Press:  18 May 2009

Fernando Bombal
Affiliation:
Departamento de Análisis Matemático, Facultad de Matemáticas, Universidad Complutense, 28040 Madrid (Spain).
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The concept of (V*) set was introduced, as a dual companion of that of (V)-set, by Pelczynski in his important paper [14]. In the same paper, the so called properties (V) and (V*) are defined by the coincidence of the (V) or (V*) sets with the weakly relatively compact sets. Many important Banach space properties are (or can be) defined in the same way; that is, by the coincidence of two classes of bounded sets. In this paper, we are concerned with the study of the class of (V*) sets in a Banach space, and its relationship with other related classes. To this general study is devoted Section I. A (as far as we know) new Banach space property (we called it property weak (V*)) is defined, by imposing the coincidence of (V*) sets and weakly conditionally compact sets. In this way, property (V*) is decomposed into the conjunction of the weak (V*) property and the weak sequential completeness. In Section II, we specialize to the study of (V*) sets in Banach lattices. The main result in the section is that every order continuous Banach lattice has property weak (V*), which extends previous results of E. and P. Saab ([16]). Finally, Section III is devoted to the study of (V*) sets in spaces of Bochner integrable functions. We characterize a broad class of (V*) sets in L1(μ, E), obtaining similar results to those of Andrews [1], Bourgain [6] and Diestel [7] for other classes of subsets. Applications to the study of properties (V*) and weak (V*) are obtained. Extension of these results to vector valued Orlicz function spaces are also given.

Type
Research Article
Copyright
Copyright © Glasgow Mathematical Journal Trust 1990

References

REFERENCES

1.Andrews, K. T., Dunford-Pettis sets in the space of Bochner integrable functions. Math. Ann., 241 (1979), 3541.CrossRefGoogle Scholar
2.Batt, J. and Hiermeyer, W., On compactness in L p(μ,X) in the weak topology and in the topology σ(L p(μ, X), L q(μ, x)). Math. Zeit. 182 (1983), 409423.CrossRefGoogle Scholar
3.Bombal, F. and Fierro, C., Compacidad débil en espacios de Orlicz de funciones vectoriales. Rev. Acad. Ci. Madrid, 78, (1984), 157163.Google Scholar
4.Bombal, F., On I 1, subspaces of Orlicz vector-valued function spaces. Math. Proc. Camb. Phil. Soc. 101 (1987), 107112.CrossRefGoogle Scholar
5.Bombal, F., On embedding l 1, as a complemented subspace of Orlicz vector-valued function spaces. Revista Matematica de la Universidad Complutense, 1 (1988), 1317.Google Scholar
6.Bourgain, J., An averaging result for l 1-sequences and applications to weakly conditionally compact sets in L x1. Israel J. Math., 32 (1979), 289298.CrossRefGoogle Scholar
7.Diestel, J., Remarks on weak compactness in L 1(μ, X)x. Glasgow Math. J., 18 (1977), 8791.CrossRefGoogle Scholar
8.Diestel, J., Sequences and series in Banach spaces, Graduate texts in Math., no. 92. Springer, 1984.CrossRefGoogle Scholar
9.Dinculeanu, N., Vector measures. (Pergamon Press, 1967).CrossRefGoogle Scholar
10.Emmanuele, G., On the Banach spaces with the property (V*) of Pelczynski. To appear in Annali Mat. Pura e Applicata.Google Scholar
11.Lindenstrauss, J. and Tzafriri, L., Classical Banach spaces I. (Springer, 1977).CrossRefGoogle Scholar
12.Lindenstrauss, J. and Tzafriri, L., Classical Banach spaces II. (Springer, 1979).CrossRefGoogle Scholar
13.Nicolescu, C. P., Weak compactness in Banach lattices. J. Operator Theory, 9 (1981), 217231.Google Scholar
14.Pelczynski, A., On Banach spaces on which every unconditionally converging operator is weakly compact. Bull. Acad. Pol. Sci., 10 (1962), 641648.Google Scholar
15.Rudin, W., Real and complex analysis, 3rd. edition (McGraw-Hill, 1987).Google Scholar
16.Saab, E. and Saab, P., On Pelcznski's property (V) and (V*) Pacific J. Math., 125 (1986), 205210.CrossRefGoogle Scholar
17.Talagrand, M., Weak Cauchy sequences in L 1(E). Amer. J. Math. 106 (1984), 703724.CrossRefGoogle Scholar
18.Tzafriri, L., Reflexivity in Banach lattices and their subspaces. J. Functional Analysis, 10 (1972), 118.CrossRefGoogle Scholar
19.Zaanen, A. C., Linear analysis (North Holland, 1953).Google Scholar