Extremal operators and oblique projections
Extremal perturbations of semi-Fredholm operators
Let T be a bounded operator on an infinite-dimensional Banach space X and Ω a compact subset of the semi-Fredholm domain of T. We construct a finite rank perturbation F such that min[dim N(T+F-λ), codim R(T+F-λ)] = 0 for all λ ∈ Ω, and which is extremal in the sense that F² = 0 and rank F = max{min[dim N(T-λ), codim R(T-λ)] : λ ∈ Ω.
Extremal problems for completely positive maps.
Extremal properties of contraction semigroups on c0 .
Extremal solutions to a class of multivalued integral equations in Banach space.
Extreme compact operators from Orlicz spaces to
Let be the subspace of finite elements of an Orlicz space endowed with the Luxemburg norm. The main theorem says that a compact linear operator is extreme if and only if on a dense subset of , where is a compact Hausdorff topological space and . This is done via the description of the extreme points of the space of continuous functions , being an Orlicz space equipped with the Orlicz norm (conjugate to the Luxemburg one). There is also given a theorem on closedness of the set of extreme...
Extreme Contraction Operators on l...
Extreme contractions on certain function spaces
Extreme contractions on C(X) and
Extreme Contractions on Real Hilbert Spaces.
Extreme extensions of positive operators
Extreme non-Arens regularity of quotients of the Fourier algebra A(G)
Extreme Norms on ...
Extreme operators on 2-dimensional -spaces
Extreme operators on AL-spaces
Extreme Points in Duals of Operator Spaces.
Extreme points in spaces of operators and vector – valued measures
Extreme points of numerical ranges of quasihyponormal operators
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 positive contractions on the Hilbert space