Results 41 to 50 of about 387 (63)

On (m, P)-expansive operators: products, perturbation by nilpotents, Drazin invertibility

open access: yesConcrete 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.
doaj   +1 more source

Approximate *-derivations and approximate quadratic *-derivations on C*-algebras

open access: yesJournal of Inequalities and Applications, 2011
In this paper, we prove the stability of *-derivations and of quadratic *-derivations on Banach *-algebras. We moreover prove the superstability of *-derivations and of quadratic *-derivations on C*-algebras.
Park Choonkil, Jang Sun
doaj  

Left Derivable Maps at Non-Trivial Idempotents on Nest Algebras

open access: yesAnnales 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
doaj   +1 more source

Combined system of additive functional equations in Banach algebras

open access: yesOpen 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
doaj   +1 more source

New aspects in polygroup theory

open access: yesAnalele 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
doaj   +1 more source

Commutators of multilinear fractional maximal operators with Lipschitz functions on Morrey spaces

open access: yesOpen 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
doaj   +1 more source

Characterizing Jordan derivations of matrix rings through zero products [PDF]

open access: yes, 2013
Let $\Mn$ be the ring of all $n \times n$ matrices over a unital ring $\mathcal{R}$, let $\mathcal{M}$ be a 2-torsion free unital $\Mn$-bimodule and let $D:\Mn\rightarrow \mathcal{M}$ be an additive map. We prove that if $D(\A)\B+ \A D(\B)+D(\B)\A+ \B D(\
Ghahramani, Hoger
core  

Generalized Derivations and Norm Equality in Normed Ideals [PDF]

open access: yes, 2011
2000 Mathematics Subject Classification: 47A10, 47A12, 47A30, 47B10, 47B20, 47B37, 47B47, 47D50.We compare the norm of a generalized derivation on a Hilbert space with the norm of its restrictions to Schatten norm ...
Barraa, Mohamed
core  

Local triple derivations on C*-algebras [PDF]

open access: yes, 2012
We prove that every bounded local triple derivation on a unital C*-algebra is a triple derivation.
Antonio   +4 more
core  

A posteriori analysis of the spectral element discretization of heat equation

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2014
In this paper, we present a posteriori analysis of the discretization of the heat equation by spectral element method. We apply Euler’s implicit scheme in time and spectral method in space.
Chorfi Nejmeddine   +2 more
doaj   +1 more source

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