Results 1 to 10 of about 253 (27)

On the compactness and the essential norm of operators defined by infinite tridiagonal matrices

open access: yesConcrete Operators, 2023
In this article, all sequences u{\boldsymbol{u}}, v{\boldsymbol{v}}, and w{\boldsymbol{w}} that define continuous and compact tridiagonal operators Tu,v,w{T}_{u,v,w} acting on the weighted sequence space lβ2{l}_{\beta }^{2} were characterized ...
Caicedo Alexander   +2 more
doaj   +1 more source

Surjective isometries on Banach sequence spaces: A survey

open access: yesConcrete Operators, 2022
In this survey, we present several results related to characterizing the surjective isometries on Banach sequence spaces. Our survey includes full proofs of these characterizations for the classical spaces as well as more recent results for combinatorial
Antunes Leandro, Beanland Kevin
doaj   +1 more source

Generalization of Darbo-type theorem and application on existence of implicit fractional integral equations in tempered sequence spaces

open access: yesAlexandria Engineering Journal, 2022
The aim of this work is to give some fixed point results based on the technique of measure of noncompactness which extend the classical Darbo’s theorem.
Anupam Das   +3 more
doaj   +1 more source

Upper bounds of some matrix operators on binomial and Orlicz-binomial double sequence spaces

open access: yesScientific African, 2022
In this article, we introduce binomial double sequence space bk(α,β;γ,δ) (1≤k≤∞) and Orlicz-binomial double sequence space bφ(α,β;γ,δ), and obtain certain inclusion results related to these spaces.
Taja Yaying, Bipan Hazarika
doaj   +1 more source

Approximation properties of tensor norms and operator ideals for Banach spaces

open access: yesOpen Mathematics, 2020
For a finitely generated tensor norm α\alpha , we investigate the α\alpha -approximation property (α\alpha -AP) and the bounded α\alpha -approximation property (bounded α\alpha -AP) in terms of some approximation properties of operator ideals.
Kim Ju Myung
doaj   +1 more source

Note on order-isomorphic isometric embeddings of some recent function spaces [PDF]

open access: yes, 2015
We investigate certain recently introduced ODE-determined varying exponent $L^p$ spaces. It turns out that these spaces are finitely representable in a concrete universal varying exponent $\ell^p$ space.
Talponen, Jarno
core   +2 more sources

Second order arithmetic means in operator ideals [PDF]

open access: yes, 2007
Equality of the second order arithmetic means of two principal ideals does not imply equality of their first order arithmetic means (second order equality cancellation).
Kaftal, Victor, Weiss, Gary
core   +1 more source

On uniform Kadec‐Klee properties and rotundity in generalized Cesàro sequence spaces

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 2, Page 91-97, 2004., 2004
We consider the generalized Cesàro sequence spaces defined by Suantai (2003) and consider it equipped with the Amemiya norm. The main purpose of this paper is to show that ces(p) equipped with the Amemiya norm is rotund and has uniform Kadec‐Klee property.
Narin Petrot, Suthep Suantai
wiley   +1 more source

Interpolation of nonlinear maps [PDF]

open access: yes, 2014
Let $(X_0, X_1)$ and $(Y_0, Y_1)$ be complex Banach couples and assume that $X_1\subseteq X_0$ with norms satisfying $\|x\|_{X_0} \le c\|x\|_{X_1}$ for some $c > 0$.
Kappeler, T.   +3 more
core   +1 more source

Contractive projections in Orlicz sequence spaces

open access: yesAbstract and Applied Analysis, Volume 2004, Issue 2, Page 133-145, 2004., 2004
We characterize norm‐one complemented subspaces of Orlicz sequence spaces ℓM equipped with either Luxemburg or Orlicz norm, provided that the Orlicz function M is sufficiently smooth and sufficiently different from the square function. We measure smoothness of M using AC1 and AC2 classes introduced by Maleev and Troyanski in 1991, and the condition for
Beata Randrianantoanina
wiley   +1 more source

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