Mapping in normed linear spaces and characterization of orthogonality problem of best approximations in 2-norm.
Measuring uncertainty without a norm.
Médianes vectorielles
Meilleure approximation en norme vectorielle et minima de Pareto
Meilleure approximation en norme vectorielle et théorie de la localisation
Meshless Polyharmonic Div-Curl Reconstruction
In this paper, we will discuss the meshless polyharmonic reconstruction of vector fields from scattered data, possibly, contaminated by noise. We give an explicit solution of the problem. After some theoretical framework, we discuss some numerical aspect arising in the problems related to the reconstruction of vector fields
Metric projections of closed subspaces of c₀ onto subspaces of finite codimension
Let X be a closed subspace of c₀. We show that the metric projection onto any proximinal subspace of finite codimension in X is Hausdorff metric continuous, which, in particular, implies that it is both lower and upper Hausdorff semicontinuous.
M-Ideals of Compact Operators.
Minimal multi-convex projections
We say that a function from is k-convex (for k ≤ L) if its kth derivative is nonnegative. Let P denote a projection from X onto V = Πₙ ⊂ X, where Πₙ denotes the space of algebraic polynomials of degree less than or equal to n. If we want P to leave invariant the cone of k-convex functions (k ≤ n), we find that such a demand is impossible to fulfill for nearly every k. Indeed, only for k = n-1 and k = n does such a projection exist. So let us consider instead a more general “shape” to preserve....
Minimal projections in tensor product spaces.
Minimal Projections in Tensor-Product Spaces.
Minimal projections onto subspaces of l∞(n) of codimension 2.
Minimal projections with respect to various norms
A theorem of Rudin permits us to determine minimal projections not only with respect to the operator norm but with respect to various norms on operator ideals and with respect to numerical radius. We prove a general result about N-minimal projections where N is a convex and lower semicontinuous (with respect to the strong operator topology) function and give specific examples for the cases of norms or seminorms of p-summing, p-integral and p-nuclear operator ideals.
Minimale Elemente auf Hyperebenen und konjugierte Funktionen
Modules of splines on polyhedral complexes.
Multiple Zeros and Applications to Optimal Linear Functionals.