Extensions of weak type multipliers
We prove that if and has compact support then Λ is a weak summability kernel for 1 < p < ∞, where is the space of multipliers of .
Extensions uniformes des formes linéaires positives
Soit un sous-espace fermé d’un espace de Banach ordonné ; ce travail propose des conditions nécessaires et suffisantes pour qu’il existe , tel que toute forme linéaire positive et continue sur admette une extension linéaire positive et continue sur , vérifiant . On termine par l’exemple d’un couple ne possédant pas la propriété précédente bien que toute forme linéaire positive continue sur se prolonge en une forme linéaire du même type en .
Extensions uniformes des opérateurs positifs
External approximation of first order variational problems via W-1,p estimates
Here we present an approximation method for a rather broad class of first order variational problems in spaces of piece-wise constant functions over triangulations of the base domain. The convergence of the method is based on an inequality involving norms obtained by Nečas and on the general framework of Γ-convergence theory.
Extraction of a “good” subsequence from a bounded sequence of integrable functions.
Extrapolation and sharp norm estimates for classical operators on weighted Lebesgue spaces.
Extrapolation functors on a family of scales generated by the real interpolation method.
Extrapolation of Sobolev imbeddings.
We survey recent results on limiting imbeddings [sic] of Sobolev spaces, particularly, those concerning weakening of assumptions on integrability of derivatives, considering spaces with dominating mixed derivatives and the case of weighted spaces.
Extrapolation theorem on Lp spaces over infinite measure space: An approach p → p0.
Extrapolation theory for the real interpolation method.
We develop an abstract extrapolation theory for the real interpolation method that covers and improves the most recent versions of the celebrated theorems of Yano and Zygmund. As a consequence of our method, we give new endpoint estimates of the embedding Sobolev theorem for an arbitrary domain Omega.
Extrapolatory description for the Lorentz and Marcinkiewicz spaces “close" to .
Extremal functions for the anisotropic Sobolev inequalities
Extremal functions of the Nevanlinna-Pick problem and Douglas algebras
The Nevanlinna-Pick problem at the zeros of a Blaschke product B having a solution of norm smaller than one is studied. All its extremal solutions are invertible in the Douglas algebra D generated by B. If B is a finite product of sparse Blaschke products (Newman Blaschke products, Frostman Blaschke products) then so are all the extremal solutions. For a Blaschke product B a formula is given for the number C(B) such that if the NP-problem has a solution of norm smaller than C(B) then all its extremal...
Extremal Maps of a Hilbert Space Equipped with a Natural Cone.
Extremal non-compactness of weighted composition operators on the disk algebra
Extremal problems for completely positive maps.
Extremal properties of the set of vector-valued Banach limits
In this manuscript we find another class of real Banach spaces which admit vector-valued Banach limits different from the classes found in [6, 7]. We also characterize the separating subsets of ℓ∞(X). For this we first need to study when the space of almost convergent sequences is closed in the space of bounded sequences, which turns out to happen only when the underlying space is complete. Finally, a study on the extremal structure of the set of vector-valued Banach limits is conducted when the...
Extremal sections of complex -balls, 0 < p ≤ 2
We study the extremal volume of central hyperplane sections of complex n-dimensional -balls with 0 < p ≤ 2. We show that the minimum corresponds to hyperplanes orthogonal to vectors ξ = (ξ¹,...,ξⁿ) ∈ ℂⁿ with |ξ¹| = ... = |ξⁿ|, and the maximum corresponds to hyperplanes orthogonal to vectors with only one non-zero coordinate.
Extremal solutions of a general marginal problem
The characterization of extremal points of the set of probability measures with given marginals is given in the general context of a marginal system. The sets of marginal uniqueness are studied and an example is added to illustrate the theory.
Extremal Structure of Convex Sets in Spaces Not Containing co.