Linear derivations on Banach *-algebras

2021 ◽  
Vol 71 (1) ◽  
pp. 27-32
Author(s):  
Husain Alhazmi ◽  
Abdul Nadim Khan
Keyword(s):  
Positive Integer ◽  
Banach Algebras ◽  
Central Idempotent

Abstract In this paper, it is shown that there is no positive integer n such that the set of x ∈ A $ x\in \mathfrak{A} $ for which [ ( x δ ) n , ( x ∗ δ ) n ( x δ ) n ] ∈ Z ( A ) $ [(x^{\delta})^n, (x^{*{\delta}})^n(x^{\delta})^n]\in \mathcal{Z}(\mathfrak{A}) $ , where δ is a linear derivation on A $ \mathfrak{A} $ or there exists a central idempotent e ∈ Q $ e\in \mathcal{Q} $ such that δ=0 on e Q $ e\mathcal{Q} $ and ( 1 − e ) Q $ (1-e)\mathcal{Q} $ satisfies S 4(X 1, X 2, X 3, X 4). Moreover, we establish other related results.

scholarly journals General solution and generalized Ulam-Hyers stability of a generalized n- type additive quadratic functional equation in Banach space and Banach algebra: direct and fixed point methods

2015 ◽  
Vol 3 (1) ◽  
pp. 25
Author(s):  
S. Murthy ◽  
M. Arunkumar ◽  
V. Govindan
Keyword(s):  
Banach Space ◽  
Functional Equation ◽  
Fixed Point ◽  
Positive Integer ◽  
General Solution ◽  
Banach Algebra ◽  
Banach Algebras ◽  
Quadratic Functional Equation ◽  
Quadratic Functional ◽  
Fixed Point Methods

<p>In this paper, the authors introduce and investigate the general solution and generalized Ulam-Hyers stability of a generalized <em>n</em>-type additive-quadratic functional equation.</p><p><br />g(x + 2y; u + 2v) + g(x 􀀀 2y; u 􀀀 2v) = 4[g(x + y; u + v) + g(x 􀀀 y; u 􀀀 v)] 􀀀 6g(x; u)<br />+ g(2y; 2v) + g(􀀀2y;􀀀2v) 􀀀 4g(y; v) 􀀀 4g(􀀀y;􀀀v)</p><p>Where  is a positive integer with , in Banach Space and Banach Algebras using direct and fixed point methods.</p>

scholarly journals A theorem on abstract Segal algebras over some commutative Banach algebras

1982 ◽  
Vol 25 (2) ◽  
pp. 293-301 ◽  
Author(s):  
U.B. Tewari ◽  
K. Parthasarathy
Keyword(s):  
Abelian Group ◽  
Positive Integer ◽  
Compact Abelian Group ◽  
Maximal Ideal ◽  
Banach Algebras ◽  
Dual Group ◽  
Locally Compact Abelian Group ◽  
Ideal Space ◽  
Locally Compact ◽  
Commutative Banach Algebras

Let B be a commutative, semi-simple, regular, Tauberian Banach algebra with noncompact maximal ideal space Δ(B). Suppose B has the property that there is a constant C such that for every compact subset K of Δ(B) there exists a f ∈ B with = 1 on K, ‖f‖B ≤ C and has compact support. We prove that if A is a proper abstract Segal algebra over B then for every positive integer n there exists f ∈ B such that fn ∉ A but fn+1 ∈ A. As a consequence of this result we prove that if G is a nondiscrete locally compact abelian group, μ a positive unbounded Radon measure on Γ (the dual group of G), 1 ≤ p < q < ∞ and , then .

The Order of Monochromatic Subgraphs with a Given Minimum Degree

10.37236/1725 ◽  
2003 ◽  
Vol 10 (1) ◽  
Author(s):  
Yair Caro ◽  
Raphael Yuster
Keyword(s):  
Positive Integer ◽  
Minimum Degree

Let $G$ be a graph. For a given positive integer $d$, let $f_G(d)$ denote the largest integer $t$ such that in every coloring of the edges of $G$ with two colors there is a monochromatic subgraph with minimum degree at least $d$ and order at least $t$. Let $f_G(d)=0$ in case there is a $2$-coloring of the edges of $G$ with no such monochromatic subgraph. Let $f(n,k,d)$ denote the minimum of $f_G(d)$ where $G$ ranges over all graphs with $n$ vertices and minimum degree at least $k$. In this paper we establish $f(n,k,d)$ whenever $k$ or $n-k$ are fixed, and $n$ is sufficiently large. We also consider the case where more than two colors are allowed.

Solvability of a 2 x 2 block operator matrix of chandrasekhar type on a Bananch algebra

Filomat ◽  
2017 ◽  
Vol 31 (16) ◽  
pp. 5169-5175 ◽  
Author(s):  
H.H.G. Hashem
Keyword(s):  
Fixed Point ◽  
Fixed Point Theorem ◽  
Existence Of Solutions ◽  
Banach Algebras ◽  
Operator Matrix ◽  
Nonlinear Operators ◽  
Block Operator Matrix ◽  
Block Operator ◽  
Quadratic Integral ◽  
Quadratic Integral Equations

In this paper, we study the existence of solutions for a system of quadratic integral equations of Chandrasekhar type by applying fixed point theorem of a 2 x 2 block operator matrix defined on a nonempty bounded closed convex subsets of Banach algebras where the entries are nonlinear operators.

Extensions of Rings Having McCoy Condition

2009 ◽  
Vol 52 (2) ◽  
pp. 267-272 ◽  
Author(s):  
Muhammet Tamer Koşan
Keyword(s):  
Positive Integer ◽  
Associative Ring ◽  
Nonzero Element ◽  
Ring Extensions

AbstractLet R be an associative ring with unity. Then R is said to be a right McCoy ring when the equation f (x)g(x) = 0 (over R[x]), where 0 ≠ f (x), g(x) ∈ R[x], implies that there exists a nonzero element c ∈ R such that f (x)c = 0. In this paper, we characterize some basic ring extensions of right McCoy rings and we prove that if R is a right McCoy ring, then R[x]/(xn) is a right McCoy ring for any positive integer n ≥ 2.

scholarly journals COMMUTATIVITY UP TO A FACTOR IN BANACH ALGEBRAS

2005 ◽  
Vol 38 (4) ◽  
pp. 895-900
Author(s):  
Christoph Schmoeger
Keyword(s):  
Banach Algebras
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