All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 12 Next

Displaying 221 – 240 of 510

Showing per page

Measure of noncompactness of linear operators between spaces of sequences that are ( N ¯ , q ) summable or bounded

Eberhard Malkowsky, V. Rakočević (2001)

Czechoslovak Mathematical Journal

In this paper we investigate linear operators between arbitrary BK spaces X and spaces Y of sequences that are ( N ¯ , q ) summable or bounded. We give necessary and sufficient conditions for infinite matrices A to map X into Y . Further, the Hausdorff measure of noncompactness is applied to give necessary and sufficient conditions for A to be a compact operator.

Multilinear Hölder-type inequalities on Lorentz sequence spaces

Daniel Carando, Verónica Dimant, Pablo Sevilla-Peris (2009)

Studia Mathematica

We establish Hölder-type inequalities for Lorentz sequence spaces and their duals. In order to achieve these and some related inequalities, we study diagonal multilinear forms in general sequence spaces, and obtain estimates for their norms. We also consider norms of multilinear forms in different Banach multilinear ideals.

Nearness relations in linear spaces

Martin Kalina (2004)

Kybernetika

In this paper, we consider nearness-based convergence in a linear space, where the coordinatewise given nearness relations are aggregated using weighted pseudo-arithmetic and geometric means and using continuous t-norms.

Nevanlinna algebras

A. Haldimann, H. Jarchow (2001)

Studia Mathematica

The Nevanlinna algebras, α p , of this paper are the L p variants of classical weighted area Nevanlinna classes of analytic functions on = z ∈ ℂ: |z| < 1. They are F-algebras, neither locally bounded nor locally convex, with a rich duality structure. For s = (α+2)/p, the algebra F s of analytic functions f: → ℂ such that ( 1 - | z | ) s | f ( z ) | → 0 as |z| → 1 is the Fréchet envelope of α p . The corresponding algebra s ∞ of analytic f: → ℂ such that s u p z ∈ ( 1 - | z | ) s | f ( z ) | < ∞ is a complete metric space but fails to be a topological vector space. F s is also...

Norm attaining multilinear forms and polynomials on preduals of Lorentz sequence spaces

M. Jimenéz Sevilla, Rafael Payá (1998)

Studia Mathematica

For each natural number N, we give an example of a Banach space X such that the set of norm attaining N-linear forms is dense in the space of all continuous N-linear forms on X, but there are continuous (N+1)-linear forms on X which cannot be approximated by norm attaining (N+1)-linear forms. Actually,X is the canonical predual of a suitable Lorentz sequence space. We also get the analogous result for homogeneous polynomials.

Normed barrelled spaces

Christopher Stuart (2000)

Banach Center Publications

In this paper we present a general “gliding hump” condition that implies the barrelledness of a normed vector space. Several examples of subspaces of l 1 are shown to be barrelled using the theorem. The barrelledness of the space of Pettis integrable functions is also implied by the theorem (this was first shown in [3]).

Currently displaying 221 – 240 of 510