Results 41 to 50 of about 103 (94)

Fractional type Marcinkiewicz integrals over non-homogeneous metric measure spaces

Journal of Inequalities and Applications, 2016
The main goal of the paper is to establish the boundedness of the fractional type Marcinkiewicz integral M β , ρ , q $\mathcal{M}_{\beta,\rho,q}$ on non-homogeneous metric measure space which includes the upper doubling and the geometrically doubling ...
Guanghui Lu, Shuangping Tao
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On (m, P)-expansive operators: products, perturbation by nilpotents, Drazin invertibility

Concrete Operators, 2021
A generalisation of m-expansive Hilbert space operators T ∈ B(ℋ) [18, 20] to Banach space operators T ∈ B(𝒳) is obtained by defining that a pair of operators A, B ∈ B(𝒳) is (m, P)-expansive for some operator P ∈ B(𝒳) if Δ A,Bm(P)= (I-LARB)m(P)=∑j=0m(-1)j(
Duggal B.P.
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Left Derivable Maps at Non-Trivial Idempotents on Nest Algebras

Annales Mathematicae Silesianae, 2019
Let Alg 𝒩 be a nest algebra associated with the nest 𝒩 on a (real or complex) Banach space 𝕏. Suppose that there exists a non-trivial idempotent P ∈ Alg 𝒩 with range P (𝕏) ∈ 𝒩, and δ : Alg 𝒩 → Alg 𝒩 is a continuous linear mapping (generalized) left ...
Ghahramani Hoger, Sattari Saman
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ON EQUALITY OF SPECTRA AND ESSENTIAL SPECRA OF OPERATORS IN HILBERT SPACES [PDF]

, 2015
It is a well known fact in operator theory that for any operator A, the essential spectrum of A is contained in the spectrum of A.  The task of finding conditions under which the two are equal has been the subject matter in a number of several research ...
LUKETERO, S.W., RUGIRI, P.G., KHALAGAI, J.M.   +2 more
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Combined system of additive functional equations in Banach algebras

Open Mathematics
In this study, we solve the system of additive functional equations: h(x+y)=h(x)+h(y),g(x+y)=f(x)+f(y),2fx+y2=g(x)+g(y),\left\{\begin{array}{l}h\left(x+y)=h\left(x)+h(y),\\ g\left(x+y)=f\left(x)+f(y),\\ 2f\left(\frac{x+y}{2}\right)=g\left(x)+g(y),\end ...
Donganont Siriluk, Park Choonkil
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New aspects in polygroup theory

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2020
The aim of this paper is to compute the commutativity degree in polygroup’s theory, more exactly for the polygroup PG and for extension of polygroups by polygroups, obtaining boundaries for them.
Sonea Andromeda Cristina
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Commutators of multilinear fractional maximal operators with Lipschitz functions on Morrey spaces

Open Mathematics
In this work, we present necessary and sufficient conditions for the boundedness of the commutators generated by multilinear fractional maximal operators on the products of Morrey spaces when the symbol belongs to Lipschitz spaces.
Zhang Pu, Ağcayazı Müjdat
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ON QUASI-INVERTIBILITY AND QUASI-SIMILARITY OF OPERATORS IN HILBERT SPACES. [PDF]

, 2015
It is a well known fact in operator Theory that if A and B are operators with at least one of them invertible then AB and BA are similar operators.  In this paper we prove an analogous result about quasi-invertible operators A and B. We thus show that if
LUKETERO, S.W., RUGIRI, P.G., KHALAGAI, J.M.   +2 more
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Contractible Kothe Co-Echelon Algebras

, 2020
In this note we investigate contractibility properties in the class of the socalled DF-algebras. We also give a complete characterization of contractible  Kothe co-echelon algebras.
Piszczek, Krzysztof
core  

AN INTERNAL CHARACTERIZATION OF COMPLETE POSITIVITY FOR ELEMENTARY OPERATORS

, 2002
Complete positivity of ‘atomically extensible’ bounded linear operators between $C^*$-algebras is characterized in terms of positivity of a bilinear form on certain finite-rank operators.
Richard M. Timoney
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