English

Boundedness and surjectivity in Banach spaces

Functional Analysis 2007-05-23 v1

Abstract

We define the (ww^\ast-) boundedness property and the (ww^\ast-) surjectivity property for sets in normed spaces. We show that these properties are pairwise equivalent in complete normed spaces by characterizing them in terms of a category-like property called (ww^\ast-) thickness. We give examples of interesting sets having or not having these properties. In particular, we prove that the tensor product of two ww^\ast-thick sets in \Xastast\Xastast and \Yast\Yast is a ww^\ast-thick subset in L(X,Y)L(X,Y)^\ast and obtain as a concequense that the set wexpBK(l2)w^\ast -exp\:B_{K(l_2)^\ast} is ww^\ast-thick.

Keywords

Cite

@article{arxiv.math/0009034,
  title  = {Boundedness and surjectivity in Banach spaces},
  author = {Olav Nygaard},
  journal= {arXiv preprint arXiv:math/0009034},
  year   = {2007}
}

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15 pages