Approximation par des variétés algébriques dans les espaces hilbertiens (Variation sur un thème de Vituškin)
Approximation pondérée sur un corps de nombres -adiques
Approximation problems in modular spaces of double sequences.
Let X denote the space of all real, bounded double sequences, and let Φ, φ, Γ be φ-functions. Moreover, let Ψ be an increasing, continuous function for u ≥ 0 such that Ψ(0) = 0.In this paper we consider some spaces of double sequences provided with two-modular structure given by generalized variations and the translation operator (...).
Approximation Results in the Strict Topology
Approximation sur le tore et irrégularité des fonctions
Approximation under an arc length constraint.
Approximation under an arc length constraint. (Short Communiaction).
Approximationseigenschaft, Lifting und Kohomologie bei lokalkonvexen Produktgarben.
Approximationszahlen von Sobolev-Einbettungen.
Aproximace a abstraktní hranice
Aproximaciones asintóticas en espacios de Banach.
Let U be an open convex set in a Banach space E, F another Banach space. We consider the space HUb(U,F) of all F-valued holomorphic functions of bounded type in U possesing an asymptotic expansion in the origin. We study classes of asymptotic approximations such that two functions in the same class with an identical asymptotic expansion must coincide. In this paper, we characterize the functions belonging to some of these classes which are optimal approximations of a given series.
Asyptotic Behaviour of Multiperiodic Functions G(x) = ... g (x/2...).
Backward adaptive biorthogonalization.
Ball proximinality of closed * subalgebras in C(Q)
The notion of ball proximinality and the strong ball proximinality were recently introduced in [2]. We prove that a closed * subalgebra A of C(Q) is strongly ball proximinal in C(Q) and the metric projection from C(Q), onto the closed unit ball of A, is Hausdorff metric continuous and hence has continuous selection.
Ball proximinality of Equable spaces.
Ball remotal subspaces of Banach spaces
We study Banach spaces X with subspaces Y whose unit ball is densely remotal in X. We show that for several classes of Banach spaces, the unit ball of the space of compact operators is densely remotal in the space of bounded operators. We also show that for several classical Banach spaces, the unit ball is densely remotal in the duals of higher even order. We show that for a separable remotal set E ⊆ X, the set of Bochner integrable functions with values in E is a remotal set in L¹(μ,X).
Banach spaces all of whose subspaces have the approximation property
Bernstein's "Lethargy" Theorem in Metrizable Topological Linear Spaces.
Best approximants for bounded functions and the lattice operations.
Best approximants from non-archimedean Stone-Weierstrass subspaces