2000 Mathematics Subject Classification: 54H05, 03E15, 46B26
We answer positively a question raised by S. Argyros: Given
any coanalytic, nonalytic subset Σ′ of the irrationals, we construct, in Mercourakis space c1(Σ′), an adequate compact which is Gul’ko and not Talagrand. Further, given any Borel, non Fσ subset Σ′ of the irrationals, we construct, in c1(Σ′), an adequate compact which is Talagrand and not Eberlein.
Supported by grants AV CR 101-90-03, and GA CR 201-01-1198...
* Supported by grants: AV ĈR 101-95-02, GAĈR 201-94-0069 (Czech Republic) and NSERC 7926 (Canada).
It is shown that the dual unit ball BX∗ of a Banach space X∗
in its weak star topology is a uniform Eberlein compact if and only if X
admits a uniformly Gâteaux smooth norm and X is a subspace of a weakly
compactly generated space. The bidual unit ball BX∗∗ of a Banach space
X∗∗ in its weak star topology is a uniform Eberlein compact if and only if
X admits a weakly uniformly rotund norm....
We transfer a renorming method of transfer, due to G. Godefroy, from weakly compactly generated Banach spaces to Vašák, i.e., weakly K-countably determined Banach spaces. Thus we obtain a new construction of a locally uniformly rotund norm on a Vašák space. A further cultivation of this method yields the new result that every dual Vašák space admits a dual locally uniformly rotund norm.
R. Deville and J. Rodríguez proved that, for every Hilbert generated space , every Pettis integrable function is McShane integrable. R. Avilés, G. Plebanek, and J. Rodríguez constructed a weakly compactly generated Banach space and a scalarly null (hence Pettis integrable) function from into , which was not McShane integrable. We study here the mechanism behind the McShane integrability of scalarly negligible functions from (mostly) into spaces. We focus in more detail on the behavior...
We show that, if μ is a probability measure and X is a Banach space, then the space L¹(μ,X) of Bochner integrable functions admits an equivalent Gâteaux (or uniformly Gâteaux) smooth norm provided that X has such a norm, and that if X admits an equivalent Fréchet (resp. uniformly Fréchet) smooth norm, then L¹(μ,X) has an equivalent renorming whose restriction to every reflexive subspace is Fréchet (resp. uniformly Fréchet) smooth.
This is a short survey on some recent as well as classical results and open problems in smoothness and renormings of Banach spaces. Applications in general topology and nonlinear analysis are considered. A few new results and new proofs are included. An effort has been made that a young researcher may enjoy going through it without any special pre-requisites and get a feeling about this area of Banach space theory. Many open problems of different level of difficulty are discussed. For the reader...
Every separable Banach space with -smooth norm (Lipschitz bump function) admits an equivalent norm (a Lipschitz bump function) which is both uniformly Gâteaux smooth and -smooth. If a Banach space admits a uniformly Gâteaux smooth bump function, then it admits an equivalent uniformly Gâteaux smooth norm.
A family of compact spaces containing continuous images of Radon-Nikod’ym compacta is introduced and studied. A family of Banach spaces containing subspaces of Asplund generated (i.e., GSG) spaces is introduced and studied. Further, for a continuous image of a Radon-Nikod’ym compact we prove: If is totally disconnected, then it is Radon-Nikod’ym compact. If is adequate, then it is even Eberlein compact.
It is shown that every strongly lattice norm on can be approximated by smooth norms. We also show that there is no lattice and Gâteaux differentiable norm on .
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