0000000000644598

AUTHOR

Märt Põldvere

showing 2 related works from this author

Banach spaces where convex combinations of relatively weakly open subsets of the unit ball are relatively weakly open

2018

We introduce and study Banach spaces which have property CWO, i.e., every finite convex combination of relatively weakly open subsets of their unit ball is open in the relative weak topology of the unit ball. Stability results of such spaces are established, and we introduce and discuss a geometric condition---property (co)---on a Banach space. Property (co) essentially says that the operation of taking convex combinations of elements of the unit ball is, in a sense, an open map. We show that if a finite dimensional Banach space $X$ has property (co), then for any scattered locally compact Hausdorff space $K$, the space $C_0(K,X)$ of continuous $X$-valued functions vanishing at infinity has…

Unit sphereMathematics::Functional AnalysisPure mathematicsWeak topology46B04 46B20General Mathematics010102 general mathematicsBanach spaceHausdorff spaceSpace (mathematics)01 natural sciencesOpen and closed mapsFunctional Analysis (math.FA)Mathematics - Functional AnalysisComplex spaceFOS: MathematicsLocally compact space0101 mathematicsVDP::Mathematics and natural science: 400MathematicsStudia Mathematica
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New applications of extremely regular function spaces

2017

Let $L$ be an infinite locally compact Hausdorff topological space. We show that extremely regular subspaces of $C_0(L)$ have very strong diameter $2$ properties and, for every real number $\varepsilon$ with $0<\varepsilon<1$, contain an $\varepsilon$-isometric copy of $c_0$. If $L$ does not contain isolated points they even have the Daugavet property, and thus contain an asymptotically isometric copy of $\ell_1$.

Mathematics::Functional AnalysisProperty (philosophy)Function spaceMathematics::Operator AlgebrasGeneral MathematicsHausdorff spaceTopological spaceLinear subspaceFunctional Analysis (math.FA)CombinatoricsMathematics - Functional AnalysisFOS: Mathematics46B20 46B22Locally compact spaceMathematicsReal number
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