Results 51 to 60 of about 455 (108)

ON THE MAXIMAL NUMERICAL RANGE OF ELEMENTARY OPERATORS

, 2017
The notion of the numerical range has been generalized in different directions. One such direction, is the maximal numerical range introduced by Stampfli (1970) to derive an identity for the norm of a derivation on L(H). Unlike the other generalizations,
Mati Runji, John Ogonji Agure, F. Nyamwala   +2 more
semanticscholar   +1 more source

On generalized derivation in Banach spaces

, 2017
In this paper we generalized two important results of B. P. Duggal [4, Theorem 2.1 and 2.6], and other results are also given. If B(X ) is the algebra of all bounded linear operators on a complex Banach space X and J (X )={x∈B(X ) : x = x1+ix2, where x1 ...
A. Mansour, S. Bouzenada
semanticscholar   +1 more source

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
doaj   +1 more source

On the numerical range of a generalized derivation

, 2017
We examine the relationship between the numerical range of the restriction of a generalized derivation to a norm ideal J and that of its implementing elements.
F. M. Runji, J. O. Agure, F. Nyamwala
semanticscholar   +1 more source

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

Journal 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  

Ideal-triangularizability and commutators of constant sign

, 2016
Let E be a Banach lattice with order continuous norm, and let A and B be positive compact operators such that the commutator AB−BA is also positive. We prove that if A and B are ideal-triangularizable, then they are simultaneously ideal-triangularizable,
R. Drnovšek, M. Kandić
semanticscholar   +1 more source

Poisson C*-algebra derivations in Poisson C*-algebras

Demonstratio Mathematica
In this study, we introduce the following additive functional equation:g(λu+v+2y)=λg(u)+g(v)+2g(y)g\left(\lambda u+v+2y)=\lambda g\left(u)+g\left(v)+2g(y) for all λ∈C\lambda \in {\mathbb{C}}, all unitary elements u,vu,v in a unital Poisson C*{C ...
Wang Yongqiao, Park Choonkil, Chang Yuan
doaj   +1 more source

Variational characterizations of weighted Hardy spaces and weighted $BMO$ spaces [PDF]

arXiv, 2020
This paper obtains new characterizations of weighted Hardy spaces and certain weighted $BMO$ type spaces via the boundedness of variation operators associated with approximate identities and their commutators, respectively.
arxiv  

Bi-additive s-functional inequalities and biderivations in modular spaces [PDF]

arXiv, 2020
In this article, by using the fixed point method, we prove the generalized Hyers--Ulam stability of biderivations from an algebra to a modular space, associated to bi-additive s-functional inequalities.
arxiv  

Existence and uniqueness of solutions for certain functional equations and system of functional equations arising in dynamic programming

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2016
This paper deals with the existence, uniqueness and iterative approximations of solutions for the functional equations and system of functional equations arising in dynamic programming of multistage decision making processes in Banach spaces and complete
Deepmala, Agarwal Ravi P.
doaj   +1 more source