Weak amenability of (2N)-th dual of a Banach algebra
M.
Ettefagh
Department of Mathematics, Tabriz Branch, Islamic Azad University, Tabriz, Iran
author
S.
Houdfar
Department of Mathematics, Tabriz Branch, Islamic Azad University, Tabriz, Iran
author
text
article
2012
eng
In this paper by using some conditions, we show that the weak amenability of (2n)-th dual of a Banach algebra A for some $n\geq 1$ implies the weak amenability of A.
Journal of Linear and Topological Algebra (JLTA)
Central Tehran Branch, Islamic Azad University
2252-0201
01
v.
02
no.
2012
55
65
http://jlta.iauctb.ac.ir/article_510112_4481b97ff2be6b5aec88a2d5db69c502.pdf
A note on uniquely (nil) clean ring
Sh.
Sahebi
Department of Mathematics, Islamic Azad University, Central Tehran Branch, PO.
Code 14168-94351, Iran
author
M.
Jahandar
Department of Mathematics, Islamic Azad University, Central Tehran Branch, PO.
Code 14168-94351, Iran
author
text
article
2012
eng
A ring R is uniquely (nil) clean in case for any $a \in R$ there exists a uniquely idempotent $e\in R$ such that $a-e$ is invertible (nilpotent). Let $C =(A V W B)$ be the Morita Context ring. We determine conditions under which the rings $A,B$ are uniquely (nil) clean. Moreover we show that the center of a uniquely (nil) clean ring is uniquely (nil) clean.
Journal of Linear and Topological Algebra (JLTA)
Central Tehran Branch, Islamic Azad University
2252-0201
01
v.
02
no.
2012
67
69
http://jlta.iauctb.ac.ir/article_510113_61313dd0e6f0354fd7ec465bb79fa807.pdf
A mathematically simple method based on denition for computing eigenvalues, generalized eigenvalues and quadratic eigenvalues of matrices
M.
Nili Ahmadabadi
Department of Mathematics, Islamic Azad University, Najafabad Branch, Iran
author
text
article
2012
eng
In this paper, a fundamentally new method, based on the denition, is introduced for numerical computation of eigenvalues, generalized eigenvalues and quadratic eigenvalues of matrices. Some examples are provided to show the accuracy and reliability of the proposed method. It is shown that the proposed method gives other sequences than that of existing methods but they still are convergent to the desired eigenvalues, generalized eigenvalues and quadratic eigenvalues of matrices. These examples show an interesting phenomenon in the procedure: The diagonal matrix that converges to eigenvalues gives them in decreasing order in the sense of absolute value. Appendices A to C provide Matlab codes that implement the proposed algorithms. They show that the proposed algorithms are very easy to program.
Journal of Linear and Topological Algebra (JLTA)
Central Tehran Branch, Islamic Azad University
2252-0201
01
v.
02
no.
2012
71
81
http://jlta.iauctb.ac.ir/article_510114_08524c96a88f2b589b9b2c9a46824457.pdf
Numerical Solution of Heun Equation Via Linear Stochastic Differential Equation
H. R.
Rezazadeh
Department of Mathematics, Karaj Branch, Islamic Azad University, PO. Code 31485-313, Karaj, Iran
author
M.
Maghasedi
Department of Mathematics, Karaj Branch, Islamic Azad University, PO. Code 31485-313,
Karaj, Iran
author
B.
shojaee
Department of Mathematics, Karaj Branch, Islamic Azad University, PO. Code 31485-313,
Karaj, Iran
author
text
article
2012
eng
In this paper, we intend to solve special kind of ordinary differential equations which is called Heun equations, by converting to a corresponding stochastic differential equation(S.D.E.). So, we construct a stochastic linear equation system from this equation which its solution is based on computing fundamental matrix of this system and then, this S.D.E. is solved by numerically methods. Moreover, its asymptotic stability and statistical concepts like expectation and variance of solutions are discussed. Finally, the attained solutions of these S.D.E.s compared with exact solution of corresponding differential equations.
Journal of Linear and Topological Algebra (JLTA)
Central Tehran Branch, Islamic Azad University
2252-0201
01
v.
02
no.
2012
83
95
http://jlta.iauctb.ac.ir/article_510120_6b263c706914ad1317cfc87ee2468b82.pdf
A New Inexact Inverse Subspace Iteration for Generalized Eigenvalue Problems
M.
Amirfakhrian
Department of Mathematics, Islamic Azad University, Central Tehran Branch, PO.
Code 14168-94351, Iran
author
F.
Mohammad
Department of Mathematics, Islamic Azad University, Central Tehran Branch, PO.
Code 14168-94351, Iran
author
text
article
2012
eng
In this paper, we represent an inexact inverse subspace iteration method for computing a few eigenpairs of the generalized eigenvalue problem Ax = Bx [Q. Ye and P. Zhang, Inexact inverse subspace iteration for generalized eigenvalue problems, Linear Algebra and its Application, 434 (2011) 1697-1715 ]. In particular, the linear convergence property of the inverse subspace iteration is preserved.
Journal of Linear and Topological Algebra (JLTA)
Central Tehran Branch, Islamic Azad University
2252-0201
01
v.
02
no.
2012
97
113
http://jlta.iauctb.ac.ir/article_510116_a6a495230d02a7daa80f2a110513ba3b.pdf
Module-Amenability on Module Extension Banach Algebras
D.
Ebrahimi bagha
Department of Mathematics, Faculty of Science, Islamic Azad University, Centeral
Tehran Branch, P. O. Box 13185/768, Tehran, Iran
author
text
article
2012
eng
Let $A$ be a Banach algebra and $E$ be a Banach $A$-bimodule then $S = A \oplus E$, the $l^1$-direct sum of $A$ and $E$ becomes a module extension Banach algebra when equipped with the algebras product $(a,x).(a^\prime,x^\prime)= (aa^\prime, a.x^\prime+ x.a^\prime)$. In this paper, we investigate $\triangle$-amenability for these Banach algebras and we show that for discrete inverse semigroup $S$ with the set of idempotents $E_S$, the module extension Banach algebra $S=l^1(E_S)\oplus l^1(S)$ is $\triangle$-amenable as a $l^1(E_S)$-module if and only if $l^1(E_S)$ is amenable as Banach algebra.
Journal of Linear and Topological Algebra (JLTA)
Central Tehran Branch, Islamic Azad University
2252-0201
01
v.
02
no.
2012
111
114
http://jlta.iauctb.ac.ir/article_510118_44c07398e7938ba779119a240cd4cf23.pdf
E-Clean Matrices and Unit-Regular Matrices
Sh. A.
Safari Sabet
Department of Mathematics, Islamic Azad University, Central Tehran Branch,Code
14168-94351, Iran
author
S.
Razaghi
Department of Mathematics, Islamic Azad University, Central Tehran Branch,Code
14168-94351, Iran
author
text
article
2012
eng
Let $a, b, k,\in K$ and $u, v \in U(K)$. We show for any idempotent $e\in K$, $(a 0|b 0)$ is e-clean iff $(a 0|u(vb + ka) 0)$ is e-clean and if $(a 0|b 0)$ is 0-clean, $(ua 0|u(vb + ka) 0)$ is too.
Journal of Linear and Topological Algebra (JLTA)
Central Tehran Branch, Islamic Azad University
2252-0201
01
v.
02
no.
2012
115
118
http://jlta.iauctb.ac.ir/article_510119_5c774e30071a0b38ec4b186ffdb5d653.pdf
Recognition of the group $G_2(5)$ by the prime graph
P.
Nosratpour
Department of mathematics, ILam Branch, Islamic Azad university, Ilam, Iran
author
M. R.
Darafsheh
School of Mathematics, statistics and Computer Science, College of Science, University of Tehran, Tehran, Iran
author
text
article
2012
eng
Let $G$ be a finite group. The prime graph of $G$ is a graph $\Gamma(G)$ with vertex set $\pi(G)$, the set of all prime divisors of $|G|$, and two distinct vertices $p$ and $q$ are adjacent by an edge if $G$ has an element of order $pq$. In this paper we prove that if $\Gamma(G)=\Gamma(G_2(5))$, then $G$ has a normal subgroup $N$ such that $\pi(N)\subseteq\{2,3,5\}$ and $G/N\equiv G_2(5)$.
Journal of Linear and Topological Algebra (JLTA)
Central Tehran Branch, Islamic Azad University
2252-0201
01
v.
02
no.
2012
115
120
http://jlta.iauctb.ac.ir/article_510117_39d0770b34588d7c09328c4a5e5401be.pdf