Central Tehran Branch. IAU
Journal of Linear and Topological Algebra (JLTA)
2252-0201
2345-5934
01
02
2012
06
01
Weak amenability of (2N)-th dual of a Banach algebra
55
65
EN
M.
Ettefagh
Department of Mathematics, Tabriz Branch, Islamic Azad University, Tabriz, Iran
minaettefagh@gmail.com
S.
Houdfar
Department of Mathematics, Tabriz Branch, Islamic Azad University, Tabriz, Iran
In this paper by using some conditions, we show that the weak amenability of (2n)-th dual of a Banach algebra A for some $ngeq 1$ implies the weak amenability of A.
Banach algebra,Arens porducts,Arens regularity,Derivation,weak amenability
http://jlta.iauctb.ac.ir/article_510112.html
http://jlta.iauctb.ac.ir/article_510112_4481b97ff2be6b5aec88a2d5db69c502.pdf
Central Tehran Branch. IAU
Journal of Linear and Topological Algebra (JLTA)
2252-0201
2345-5934
01
02
2012
06
01
A note on uniquely (nil) clean ring
67
69
EN
Sh.
Sahebi
Department of Mathematics, Islamic Azad University, Central Tehran Branch, PO.
Code 14168-94351, Iran
M.
Jahandar
Department of Mathematics, Islamic Azad University, Central Tehran Branch, PO.
Code 14168-94351, Iran
m66.jahandar@gmail.com
A ring R is uniquely (nil) clean in case for any $a in R$ there exists a uniquely idempotent $ein R$ 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.
Full element,uniquely clean ring,nil clean ring
http://jlta.iauctb.ac.ir/article_510113.html
http://jlta.iauctb.ac.ir/article_510113_61313dd0e6f0354fd7ec465bb79fa807.pdf
Central Tehran Branch. IAU
Journal of Linear and Topological Algebra (JLTA)
2252-0201
2345-5934
01
02
2012
06
01
A mathematically simple method based on denition for computing eigenvalues, generalized eigenvalues and quadratic eigenvalues of matrices
71
81
EN
M.
Nili Ahmadabadi
Department of Mathematics, Islamic Azad University, Najafabad Branch, Iran
nili@phu.iaun.ac.ir
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.
Eigenvalue,Generalized eigenvalue,Quadratic eigenvalue,Numerical computation,Iterative method
http://jlta.iauctb.ac.ir/article_510114.html
http://jlta.iauctb.ac.ir/article_510114_08524c96a88f2b589b9b2c9a46824457.pdf
Central Tehran Branch. IAU
Journal of Linear and Topological Algebra (JLTA)
2252-0201
2345-5934
01
02
2012
06
01
Numerical Solution of Heun Equation Via Linear Stochastic Differential Equation
83
95
EN
H. R.
Rezazadeh
Department of Mathematics, Karaj Branch, Islamic Azad University, PO. Code 31485-313, Karaj, Iran
h-rezazadeh@kiau.ac.ir
M.
Maghasedi
Department of Mathematics, Karaj Branch, Islamic Azad University, PO. Code 31485-313,
Karaj, Iran
maghasedi@kiau.ac.ir
B.
shojaee
Department of Mathematics, Karaj Branch, Islamic Azad University, PO. Code 31485-313,
Karaj, Iran
shoujaei@kiau.ac.ir
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.
Heun equation,Wiener process,Stochastic differential equation,Linear equations system
http://jlta.iauctb.ac.ir/article_510120.html
http://jlta.iauctb.ac.ir/article_510120_6b263c706914ad1317cfc87ee2468b82.pdf
Central Tehran Branch. IAU
Journal of Linear and Topological Algebra (JLTA)
2252-0201
2345-5934
01
02
2012
06
01
A New Inexact Inverse Subspace Iteration for Generalized Eigenvalue Problems
97
113
EN
M.
Amirfakhrian
Department of Mathematics, Islamic Azad University, Central Tehran Branch, PO.
Code 14168-94351, Iran
majiamir@yahoo.com
F.
Mohammad
Department of Mathematics, Islamic Azad University, Central Tehran Branch, PO.
Code 14168-94351, Iran
f.mohammad456@yahoo.com
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.
Eigenvalue problem,inexact inverse iteration,subspace iteration,inner-outer iteration,approximation,Convergence
http://jlta.iauctb.ac.ir/article_510116.html
http://jlta.iauctb.ac.ir/article_510116_a6a495230d02a7daa80f2a110513ba3b.pdf
Central Tehran Branch. IAU
Journal of Linear and Topological Algebra (JLTA)
2252-0201
2345-5934
01
02
2012
06
01
Module-Amenability on Module Extension Banach Algebras
111
114
EN
D.
Ebrahimi bagha
Department of Mathematics, Faculty of Science, Islamic Azad University, Centeral
Tehran Branch, P. O. Box 13185/768, Tehran, Iran
dav.ebrahimibagha@iauctb.ac.ir
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.
Module-amenability,module extension,Banach algebras
http://jlta.iauctb.ac.ir/article_510118.html
http://jlta.iauctb.ac.ir/article_510118_44c07398e7938ba779119a240cd4cf23.pdf
Central Tehran Branch. IAU
Journal of Linear and Topological Algebra (JLTA)
2252-0201
2345-5934
01
02
2012
06
01
E-Clean Matrices and Unit-Regular Matrices
115
118
EN
Sh. A.
Safari Sabet
Department of Mathematics, Islamic Azad University, Central Tehran Branch,Code
14168-94351, Iran
S.
Razaghi
Department of Mathematics, Islamic Azad University, Central Tehran Branch,Code
14168-94351, Iran
Let $a, b, k,in K$ and $u, v in U(K)$. We show for any idempotent $ein K$, $(a 0|b 0)$ 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.
Matrix ring,unimodular column,unit-regular,clean,e-clean
http://jlta.iauctb.ac.ir/article_510119.html
http://jlta.iauctb.ac.ir/article_510119_5c774e30071a0b38ec4b186ffdb5d653.pdf
Central Tehran Branch. IAU
Journal of Linear and Topological Algebra (JLTA)
2252-0201
2345-5934
01
02
2012
06
01
Recognition of the group $G_2(5)$ by the prime graph
115
120
EN
P.
Nosratpour
Department of mathematics, ILam Branch, Islamic Azad university, Ilam, Iran
p.nosratpour@ilam-iau.ac.ir
M. R.
Darafsheh
School of Mathematics, statistics and Computer Science, College of Science, University of Tehran, Tehran, Iran
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 $G/Nequiv G_2(5)$.
prime graph,recognition,linear group
http://jlta.iauctb.ac.ir/article_510117.html
http://jlta.iauctb.ac.ir/article_510117_39d0770b34588d7c09328c4a5e5401be.pdf