Extreme Points of Convex Sets.
Extreme points of the Besicovitch--Orlicz space of almost periodic functions equipped with the Luxemburg norm
We investigate which points in the unit sphere of the Besicovitch--Orlicz space of almost periodic functions, equipped with the Luxemburg norm, are extreme points. Sufficient conditions for the strict convexity of this space are also given.
Extreme points of the closed unit ball in C*-algebras
In this short note we give a short and elementary proof of a characterization of those extreme points of the closed unit ball in C*-algebras which are unitary. The result was originally proved by G. K. Pedersen using some methods from the theory of approximation by invertible elements.
Extreme points of the complex binary trilinear ball
We characterize all the extreme points of the unit ball in the space of trilinear forms on the Hilbert space . This answers a question posed by R. Grząślewicz and K. John [7], who solved the corresponding problem for the real Hilbert space . As an application we determine the best constant in the inequality between the Hilbert-Schmidt norm and the norm of trilinear forms.
Extreme points of the positive part of the unit ball and strictly monotone norm.
Extreme points of the unit cell in Lebesgue-Bochner function spaces
Extreme positive functionals
Extreme Positive Linear Maps on C*-Algebras.
Extreme positive operators on involution algebras
Extreme Punkte in der Einheitskugel des Vektorraumes der trigonometrischen Prolynome.
Extreme spectral states and multiplicative extensions in Banach algebras
Extreme Spectral States of Commutative Banach Algebras.
Extreme symmetric norms on
Extreme topological measures
It has been an open question since 1997 whether, and under what assumptions on the underlying space, extreme topological measures are dense in the set of all topological measures on the space. The present paper answers this question. The main result implies that extreme topological measures are dense on a variety of spaces, including spheres, balls and projective planes.
Extremely non-complex Banach spaces
A Banach space X is said to be an extremely non-complex space if the norm equality ∥Id +T 2∥ = 1+∥T 2∥ holds for every bounded linear operator T on X. We show that every extremely non-complex Banach space has positive numerical index, it does not have an unconditional basis and that the infimum of diameters of the slices of its unit ball is positive.
Extremely Non-Nice Operators into CK and Continuous Mappings into the Hilbert Cube.
F. Riesz a matematika dvacátého století
Faces complémentables dans un cône
Facial Structure of the Sum of Two Compact Convex Sets.
Facial structures of separable and PPT states
A positive semi-definite block matrix (a state if it is normalized) is said to be separable if it is the sum of simple tensors of positive semi-definite matrices. A state is said to be entangled if it is not separable. It is very difficult to detect the border between separable and entangled states. The PPT (positive partial transpose) criterion tells us that the partial transpose of a separable state is again positive semi-definite, as was observed by M. D. Choi in 1982 from...