Results 1 to 10 of about 1,200,505 (78)

Boundaries and Polyhedral Banach Spaces [PDF]

open access: yesProceedings of the American Mathematical Society, 2015
We show that if X X and Y Y are Banach spaces, where Y Y is separable and polyhedral, and if T : X → Y T:X\to Y is a bounded linear operator such that T ∗ ( Y ∗ )
S Troyanski
exaly   +5 more sources

On the Numerical Index of Polyhedral Banach Spaces [PDF]

open access: yesLinear Algebra and Its Applications, 2019
The computation of the numerical index of a Banach space is an intriguing problem, even in case of two-dimensional real polyhedral Banach spaces. In this article we present a general method to estimate the numerical index of any finite-dimensional real polyhedral Banach space, by considering the action of only finitely many functionals, on the unit ...
Kallol Paul, Debmalya Sain, Santanu Bag
exaly   +6 more sources

A Note on Polyhedral Banach Spaces [PDF]

open access: yesProceedings of the American Mathematical Society, 1972
We give a sufficient condition for an infinitedimensional Banach space X to be polyhedral. If X
Gleit, Alan, McGuigan, Robert
exaly   +4 more sources

Smooth and Polyhedral Approximation in Banach Spaces [PDF]

open access: yesJournal of Mathematical Analysis and Applications, 2016
We show that norms on certain Banach spaces $X$ can be approximated uniformly, and with arbitrary precision, on bounded subsets of $X$ by $C^{\infty}$ smooth norms and polyhedral norms. In particular, we show that this holds for any equivalent norm on $c_0(Γ)$, where $Γ$ is an arbitrary set.
Richard J Smith
exaly   +5 more sources

K-Smoothness on Polyhedral Banach Spaces [PDF]

open access: yesColloquium Mathematicum, 2022
11 ...
Arpita Mal, Kallol Paul
exaly   +3 more sources

Structure of Pareto Solutions of Generalized Polyhedral-Valued Vector Optimization Problems in Banach Spaces [PDF]

open access: yesAbstract and Applied Analysis, 2013
In general Banach spaces, we consider a vector optimization problem (SVOP) in which the objective is a set-valued mapping whose graph is the union of finitely many polyhedra or the union of finitely many generalized polyhedra.
Qinghai He, Weili Kong
doaj   +4 more sources

Best Approximation in Polyhedral Banach Spaces

open access: yesJournal of Approximation Theory, 2011
The authors study conditions under which the metric projection of a polyhedral Banach space \(X\) onto a closed subspace \(Y\) is Hausdorff lower or upper semicontinuous. The paper is organized as follows. Section 0 is an introduction. Section 1 contains notation concerning Banach spaces, followed by definitions and preliminary facts on polyhedral ...
Libor Vesely   +2 more
exaly   +2 more sources

Polyhedral Norms on Non-Separable Banach Spaces

open access: yesJournal of Functional Analysis, 2008
A Banach space \(X\) is called polyhedral if the unit ball of each of its finite-dimensional subspaces is a polytope. Separable polyhedral spaces were investigated in detail; see, e.g., [\textit{V. P. Fonf, J.\,Lindenstrauss} and \textit{R. P. Phelps}, in: Handbook of the Geometry of Banach spaces, Vol.\ I, Elsevier, 599--670 (2001; Zbl 1086.46004 ...
S Troyanski
exaly   +2 more sources

Extension of Isometries Between Unit Spheres of Finite-Dimensional Polyhedral Banach Spaces

open access: yesJournal of Mathematical Analysis and Applications, 2012
We prove that an onto isometry between unit spheres of finite-dimensional polyhedral Banach spaces extends to a linear isometry of the corresponding spaces.
Vladimir Kadets, Miguel Martín
exaly   +4 more sources

Polyhedral Direct Sums of Banach Spaces, and Generalized Centers of Finite Sets

open access: yesJournal of Mathematical Analysis and Applications, 2012
Let \(X\) be a real Banach space. \(X\) is said to satisfy \((GC)\) if for every \(n\) and for every real-valued continuous, nondecreasing coercive function \(f\) on \( [0,\infty)^n\), the set \(E_f(a)\) of minimizers of the function \(\phi(x) = f(\|x-a_1\|,\dots,\|x-a_n\|)\) is nonempty, where \(x \in X\) and \(a= (a_1,\dots,a_n) \in X^n\).
Libor Vesely
exaly   +2 more sources

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