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Fractional difference sequence spaces have been studied in the literature recently. In this work, some identities or estimates for the operator norms and the Hausdorff measures of noncompactness of certain operators on some difference…

Functional Analysis · Mathematics 2019-02-22 Faruk Özger

In this paper, we apply the Hausdorff measure of noncompactness to obtain the necessary and sufficient conditions for certain matrix operators on the Fibonacci difference sequence spaces l_{p}(F) and l_{infinite}(F) to be compact, where…

Functional Analysis · Mathematics 2013-09-03 E. E. Kara , M. Başarır , M. Mursaleen

The aim of the paper is to introduce the spaces $\ell_{\infty}^{\lambda}(\widehat{F})$ and $\ell_{p}^{\lambda}(\widehat{F})$ derived by the composition of the two infinite matrices $\Lambda=(\lambda_{nk})$ and $\widehat{F}=\left( f_{nk}…

Functional Analysis · Mathematics 2017-06-23 Anupam Das , Bipan Hazarika , Feyzi Başar

This paper presents new sequence spaces $X(r, s, t, p ; B)$ for $X \in \{l_\infty(p), c(p), c_0(p), l(p)\}$ defined by using generalized means and difference operator. It is shown that these spaces are complete paranormed spaces and the…

Functional Analysis · Mathematics 2013-07-24 Amit Maji , Atanu Manna , P. D. Srivastava

We consider sequences of operators $U_n:L^1(X)\to M(X)$, where $X$ is a space of homogeneous type. Under certain conditions on the operators $U_n$ we give a complete characterization of convergence (divergence) sets of functional sequences…

Classical Analysis and ODEs · Mathematics 2025-12-09 Grigori A. Karagulyan

In the given paper we first introduce $\bar{N}_{\Delta^{-}}^{q}$ summable difference sequence spaces and prove some properties of these spaces. We then obtain the necessary and sufficient conditions for infinite matrices $A$ to map these…

Functional Analysis · Mathematics 2018-09-26 Ishfaq Ahmad Malik , Tanweer Jalal

In this research article, we establish some identities and estimates for the operator norms and the Hausdorff measures of noncompactness of certain operators on some lacunary difference sequence spaces defined by Orlicz function. Moreover,…

Functional Analysis · Mathematics 2015-06-19 Ekrem Savas , Stuti Borgohain

In this paper, new sequence spaces $X(r, s, t ;\Delta^{(m)})$ for $X\in \{l_\infty, c, c_0\}$ defined by using generalized means and difference operator of order $m$ are introduced. It is shown that these spaces are complete normed linear…

Functional Analysis · Mathematics 2013-07-24 Amit Maji , Atanu Manna , P. D. Srivastava

Let $A$ be a Banach space, $p>1$, and $1/p+1/q=1$. If a sequence $a=(a_i)$ in $A$ has a finite $p$-sum, then the operator $\Lambda_a:\ell^q\to A$, defined by $\Lambda_a(\beta)=\sum_{i=1}^\infty \beta_i a_i, \beta=(\beta_i)\in \ell^q$, is…

Functional Analysis · Mathematics 2025-06-10 Mortaza Abtahi

This paper intends to develop a $q$-difference operator $\nabla^{(\gamma)}_q$ of fractional order $\gamma$, and give several intriguing properties of this new difference operator. Our main focus remains on the construction of sequence…

Functional Analysis · Mathematics 2025-11-25 Taja Yaying , Pinakadhar Baliarsingh , Bipan Hazarika

The main purpose of this article is to introduce Pascal difference sequence spaces of fractional order $ \tau $ over the sequence space $\ell_p$ and $\ell_\infty$. Some topological properties of these spaces are considered here along with…

Functional Analysis · Mathematics 2023-03-07 Salila Dutta , Diptimayee Jena

We have introduced a new sequence space $l(r, s, t, p ;\Delta^{(m)})$ combining by using generalized means and difference operator of order $m$. We have shown that the space $l(r, s, t, p ;\Delta^{(m)})$ is complete under some suitable…

Functional Analysis · Mathematics 2016-01-05 Amit Maji , P. D. Srivastava

In this paper we first define the $\bar{N}(p,q)$ summable sequence spaces and obtain some basic results related to these spaces. The necessary and sufficient conditions for infinite matrices $A$ to map these spaces on $X~~,~~X=c_0, c \text{…

Functional Analysis · Mathematics 2018-05-16 Ishfaq Ahmad Malik , Tanweer Jalal

It is well known that weakly $p$-summable sequences in a Banach space $E$ are associated to bounded operators from $\ell_{p^*}$ to $E$, and unconditionally $p$-summable sequences in $E$ are associated to compact operators from $\ell_{p^*}$…

Functional Analysis · Mathematics 2024-03-07 Geraldo Botelho , Ariel S. Santiago

We obtain a complete characterization of the bounded Hausdorff operators acting on a Fock space $F^p_\alpha$ and taking its values into a larger one $F^q_\alpha,\ 0 < p \leq q \leq \infty,$ as well as some necessary or sufficient conditions…

Functional Analysis · Mathematics 2023-10-05 Óscar Blasco , Antonio Galbis

To a generalized tight continuous frame in a Hilbert space $\H$ indexed by a locally compact space $\Si$ endowed with a Radon measure, one associates a coorbit theory converting spaces of functions on $\Si$ in spaces of vectors comparable…

Functional Analysis · Mathematics 2014-06-30 M. Mantoiu , D. Parra

In this paper we introduce and study some Hilbert-type operators acting from the function spaces into the sequence spaces. We give some sufficient and necessary conditions for the boundedness and compactness of these Hilbert-type operators.…

Functional Analysis · Mathematics 2023-12-27 Jianjun Jin

The main objective of this article is to introduce Euler-Riesz difference sequence spaces of fractional order ${\tau} $ along with infinite matrices. Some topological properties of these spaces are considered here along with the Schauder…

Functional Analysis · Mathematics 2023-01-18 D. Jena , S. Dutta

The purpose of this paper is to systematically study compactness and essential norm properties of operators on a very general class of weighted Fock spaces over $\C$. In particular, we obtain rather strong necessary and sufficient…

Functional Analysis · Mathematics 2014-04-09 Joshua Isralowitz

In this paper, we present intriguing findings that characterize both the closed (unbounded) and bounded EP operators on Hilbert spaces. Additionally, we demonstrate the result $\gamma(T) \leq r(T)$, where $T$ is a bounded EP operator, and…

Functional Analysis · Mathematics 2024-12-10 Arup Majumdar , P. Sam Johnson
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