On some geometric constants and the fixed point property for multivalued nonexpansive mappings.
On some geometric properties concerning closed convex sets.
In this article, we consider the (weak) drop property, weak property (a), and property (w) for closed convex sets. Here we give some relations between those properties. Particularly, we prove that C has (weak) property (a) if and only if the subdifferential mapping of Cº is (n-n) (respectively, (n-w)) upper semicontinuous and (weak) compact valued. This gives an extension of a theorem of Giles and the first author.
On some geometric properties in C(K,X) and C(K,X)*.
On some geometric properties of certain Köthe sequence spaces
It is proved that if a Kothe sequence space is monotone complete and has the weakly convergent sequence coefficient WCS, then is order continuous. It is shown that a weakly sequentially complete Kothe sequence space is compactly locally uniformly rotund if and only if the norm in is equi-absolutely continuous. The dual of the product space of a sequence of Banach spaces , which is built by using an Orlicz function satisfying the -condition, is computed isometrically (i.e. the exact...
On some global and local geometric properties of Calderón-Lozanovskiĭ spaces
Criteria for full k-rotundity (k ∈ ℕ, k ≥ 2) and uniform rotundity in every direction of Calderón-Lozanovskiĭ spaces are formulated. A characterization of -points in these spaces is also given.
On some local geometry of Musielak-Orlicz sequence spaces equipped with the Luxemburg norm
Criteria for strong U-points, compactly locally uniformly rotund points, weakly compactly locally uniformly rotund points and locally uniformly rotund points in Musielak-Orlicz sequence spaces equipped with the Luxemburg norm are given.
On some parameters associated with normed lattices and on series characterization of M-spaces
On some properties for dual spaces of Musielak-Orlicz function spaces
We will present relationships between the modular ρ* and the norm in the dual spaces in the case when a Musielak-Orlicz space is equipped with the Orlicz norm. Moreover, criteria for extreme points of the unit sphere of the dual space will be presented.
On some subsets of
On spaces with local unconditional structure
On spreading -sequences in Banach spaces
We introduce and study the spreading-(s) and the spreading-(u) property of a Banach space and their relations. A space has the spreading-(s) property if every normalized weakly null sequence has a subsequence with a spreading model equivalent to the usual basis of ; while it has the spreading-(u) property if every weak Cauchy and non-weakly convergent sequence has a convex block subsequence with a spreading model equivalent to the summing basis of . The main results proved are the following: (a)...
On spreading models in
On strictly convex and strictly 2-convex 2-normed spaces. II.
On Strongly WCG Banach Spaces.
On subspaces of Banach spaces where every functional has a unique norm-preserving extension
Let X be a Banach space and Y a closed subspace. We obtain simple geometric characterizations of Phelps' property U for Y in X (that every continuous linear functional g ∈ Y* has a unique norm-preserving extension f ∈ X*), which do not use the dual space X*. This enables us to give an intrinsic geometric characterization of preduals of strictly convex spaces close to the Beauzamy-Maurey-Lima-Uttersrud criterion of smoothness. This also enables us to prove that the U-property of the subspace K(E,F)...
On subspaces of L1 which embed into ...1.
On super-weakly compact sets and uniformly convexifiable sets
This paper mainly concerns the topological nature of uniformly convexifiable sets in general Banach spaces: A sufficient and necessary condition for a bounded closed convex set C of a Banach space X to be uniformly convexifiable (i.e. there exists an equivalent norm on X which is uniformly convex on C) is that the set C is super-weakly compact, which is defined using a generalization of finite representability. The proofs use appropriate versions of classical theorems, such as James' finite tree...
On supportless absorbing convex subsets in normed spaces
It is proved that a separable normed space contains a closed bounded convex symmetric absorbing supportless subset if and only if this space may be covered (in its completion) by the range of a nonisomorphic operator.
On the Aleksandrov-Rassias problem and the Hyers-Ulam-Rassias stability problem.
On the automorphisms of circular and Reinhardt domains in complex Banach spaces.