ORIGINAL_ARTICLE
On the spectra of some matrices derived from two quadratic matrices
begin{abstract} The relations between the spectrum of the matrix $Q+R$ and the spectra of the matrices $(gamma + delta)Q+(alpha + beta)R-QR-RQ$, $QR-RQ$, $alpha beta R-QRQ$, $alpha RQR-(QR)^{2}$, and $beta R-QR$ have been given on condition that the matrix $Q+R$ is diagonalizable, where $Q$, $R$ are ${alpha, beta}$-quadratic matrix and ${gamma, delta}$-quadratic matrix, respectively, of order $n$. end{abstract}
http://bims.iranjournals.ir/article_337_6b4319d54520d67fc847630c7c2cac10.pdf
2013-05-01T11:23:20
2019-01-19T11:23:20
225
238
Quadratic matrix
idempotent matrix
spectrum
linear combination
diagonalization
H.
Ozdemir
hozdemir@sakarya.edu.tr
true
1
Department of Mathematics, University of Sakarya, TR54187, Sakarya, Turkey
Department of Mathematics, University of Sakarya, TR54187, Sakarya, Turkey
Department of Mathematics, University of Sakarya, TR54187, Sakarya, Turkey
LEAD_AUTHOR
T.
Petik
petiktugba@hotmail.com
true
2
Department of Mathematics, University of Sakarya,TR54187, Sakarya, Turkey
Department of Mathematics, University of Sakarya,TR54187, Sakarya, Turkey
Department of Mathematics, University of Sakarya,TR54187, Sakarya, Turkey
AUTHOR
ORIGINAL_ARTICLE
The least-square bisymmetric solution to a quaternion matrix equation with applications
In this paper, we derive the necessary and sufficient conditions for the quaternion matrix equation XA=B to have the least-square bisymmetric solution and give the expression of such solution when the solvability conditions are met. Futhermore, we consider the maximal and minimal inertias of the least-square bisymmetric solution to this equation. As applications, we derive sufficient and necessary conditions for XA=B to have the positive (nonnegative) definite least-square bisymmetric solution and the maximal (minimal) least-square bisymmetric solution.
http://bims.iranjournals.ir/article_340_5bfe11787a82c95ca80797926f05c97f.pdf
2013-05-15T11:23:20
2019-01-19T11:23:20
239
257
Quaternion matrix equation
bisymmetric matrix
least-square solution
Inertia
Q.
Wang
wqw858@yahoo.com.cn
true
1
Department of Mathematics, Shanghai University
Department of Mathematics, Shanghai University
Department of Mathematics, Shanghai University
LEAD_AUTHOR
G.
Yu
yuguihai@126.com
true
2
Department of Mathematics, Shanghai University
Department of Mathematics, Shanghai University
Department of Mathematics, Shanghai University
AUTHOR
ORIGINAL_ARTICLE
Optimal convex combinations bounds of centrodial and harmonic means for logarithmic and identric means
We find the greatest values $alpha_{1} $ and $alpha_{2} $, and the least values $beta_{1} $ and $beta_{2} $ such that the inequalities $alpha_{1} C(a,b)+(1-alpha_{1} )H(a,b)0$ with $aneq b$. Here, $C(a,b)$, $H(a,b)$, $L(a,b)$, and $I(a,b)$ are the centroidal, harmonic, logarithmic, and identric means of two positive numbers $a$ and $b$, respectively.
http://bims.iranjournals.ir/article_411_ce7ebf9563324f84f8dface04487e196.pdf
2013-05-15T11:23:20
2019-01-19T11:23:20
259
269
logarithmic mean
identric mean
centroidal mean
harmonic mean
Y.
Chu
chuyuming@hutc.zj.cn
true
1
Huzhou Teachers College
Huzhou Teachers College
Huzhou Teachers College
LEAD_AUTHOR
S.
Hou
houshouwei2008@163.com
true
2
Huzhou Teachers College
Huzhou Teachers College
Huzhou Teachers College
AUTHOR
W.
Xia
xwf212@hutc.zj.cn
true
3
Huzhou Teachers College
Huzhou Teachers College
Huzhou Teachers College
AUTHOR
ORIGINAL_ARTICLE
Finite groups with three relative commutativity degrees
For a finite group $G$ and a subgroup $H$ of $G$, the relative commutativity degree of $H$ in $G$, denoted by $d(H,G)$, is the probability that an element of $H$ commutes with an element of $G$. Let $mathcal{D}(G)={d(H,G):Hleq G}$ be the set of all relative commutativity degrees of subgroups of $G$. It is shown that a finite group $G$ admits three relative commutativity degrees if and only if $G/Z(G)$ is a non-cyclic group of order $pq$, where $p$ and $q$ are primes. Moreover, we determine all the relative commutativity degrees of some known groups.
http://bims.iranjournals.ir/article_412_c7a8a12e199ac1ff4482cfd330bf4466.pdf
2013-05-15T11:23:20
2019-01-19T11:23:20
271
280
Commutativity degree
relative commutativity degree
isoclinism
relative isoclinism
R.
Barzegar
ro.gbps@gmail.com
true
1
Ferdowsi University of Mashhad
Ferdowsi University of Mashhad
Ferdowsi University of Mashhad
AUTHOR
A.
Erfanian
erfanian@math.um.ac.ir
true
2
Ferdowsi University of Mashhad
Ferdowsi University of Mashhad
Ferdowsi University of Mashhad
LEAD_AUTHOR
M.
Farrokhi D. G.
m.farrokhi.d.g@gmail.com
true
3
Ferdowsi University of Mashhad
Ferdowsi University of Mashhad
Ferdowsi University of Mashhad
AUTHOR
ORIGINAL_ARTICLE
Gorenstein flat and Gorenstein injective dimensions of simple modules
Let R be a right GF-closed ring with finite left and right Gorenstein global dimension. We prove that if I is an ideal of R such that R/I is a semi-simple ring, then the Gorensntein flat dimensnion of R/I as a right R-module and the Gorensntein injective dimensnnion of R/I as a left R-module are identical. In particular, we show that for a simple module S over a commutative Gorensntein ring R, the Gorenstein flat dimension of S equals to the Gorenstein injective dimension of S.
http://bims.iranjournals.ir/article_413_0c2096907897563917352df573b7123b.pdf
2013-05-15T11:23:20
2019-01-19T11:23:20
281
287
Gorenstein flat dimension
Gorenstein injective dimension
simple module
A.
Xu
xuaimin88888@126.com
true
1
Department of Mathematics,
Nanjing University
Department of Mathematics,
Nanjing University
Department of Mathematics,
Nanjing University
AUTHOR
X.
Yan
yanxg1109@sina.cn
true
2
School of Mathematics & Information Technology,
Nanjing Xiaozhuang University
School of Mathematics & Information Technology,
Nanjing Xiaozhuang University
School of Mathematics & Information Technology,
Nanjing Xiaozhuang University
LEAD_AUTHOR
ORIGINAL_ARTICLE
Quasirecognition by the prime graph of L_3(q) where 3 < q < 100
Let $G$ be a finite group. We construct the prime graph of $ G $,which is denoted by $ Gamma(G) $ as follows: the vertex set of thisgraph is the prime divisors of $ |G| $ and two distinct vertices $ p$ and $ q $ are joined by an edge if and only if $ G $ contains anelement of order $ pq $.In this paper, we determine finite groups $ G $ with $ Gamma(G) =Gamma(L_3(q)) $, $2 leq q < 100 $ and prove that if $ q neq 2, 3$, then $L_3(q) $ is quasirecognizable by prime graph, i.e., if $G$is a finite group with the same prime graph as the finite simplegroup $L_3(q)$, then $G$ has a unique non-Abelian composition factorisomorphic to $L_3(q)$. As a consequence of our results we provethat the simple group $L_{3}(4)$ is recognizable and the simplegroups $L_{3}(7)$ and $L_{3}(9)$ are $2-$recognizable by the primegraph.
http://bims.iranjournals.ir/article_414_abb286fd32fe231f0647dce9cdb1cae2.pdf
2013-05-01T11:23:20
2019-01-19T11:23:20
289
305
Prime graph
element order
simple group
linear group
S. S.
Salehi Amiri
salehisss@yahoo.com
true
1
Islamic Azad University
Islamic Azad University
Islamic Azad University
AUTHOR
A.
Khalili Asboei
alirezakhas@gmail.com
true
2
Islamic Azad University
Islamic Azad University
Islamic Azad University
AUTHOR
A.
Iranmanesh
iranmana@yahoo.com
true
3
Tarbiat Modares University
Tarbiat Modares University
Tarbiat Modares University
LEAD_AUTHOR
A.
Tehranian
tehranian1340@yahoo.com
true
4
Islamic Azad University
Islamic Azad University
Islamic Azad University
AUTHOR
ORIGINAL_ARTICLE
Existence of positive solutions for a boundary value problem of a nonlinear fractional differential equation
This paper presents conditions for the existence and multiplicity of positive solutions for a boundary value problem of a nonlinear fractional differential equation. We show that it has at least one or two positive solutions. The main tool is Krasnosel'skii fixed point theorem on cone and fixed point index theory.
http://bims.iranjournals.ir/article_415_bcc9076ae61d66e52701f70a718d0c42.pdf
2013-05-15T11:23:20
2019-01-19T11:23:20
307
323
Caputo derivative
cone
fixed point theorem
Fractional differential equation
positive solutions
F.
Torres
francisco.torres@uda.cl
true
1
Departamento de Matematica
Universidad de Atacama
Departamento de Matematica
Universidad de Atacama
Departamento de Matematica
Universidad de Atacama
LEAD_AUTHOR
ORIGINAL_ARTICLE
On H-cofinitely supplemented modules
A module $M$ is called $emph{H}$-cofinitely supplemented if for every cofinite submodule $E$ (i.e. $M/E$ is finitely generated) of $M$ there exists a direct summand $D$ of $M$ such that $M = E + X$ holds if and only if $M = D + X$, for every submodule $X$ of $M$. In this paper we study factors, direct summands and direct sums of $emph{H}$-cofinitely supplemented modules. Let $M$ be an $emph{H}$-cofinitely supplemented module and let $N leq M$ be a submodule. Suppose that for every direct summand $K$ of $M$, $(N + K)/N$ lies above a direct summand of $M/N$. Then $M/N$ is $emph{H}$-cofinitely supplemented. Let $M$ be an $emph{H}$-cofinitely supplemented module. Let $N$ be a direct summand of $M$. Suppose that for every direct summand $K$ of $M$ with $M=N+K$, $Ncap K$ is also a direct summand of $M$. Then $N$ is $emph{H}$-cofinitely supplemented. Let $M = M_{1} oplus M_{2}$. If $M_{1}$ is radical $M_{2}$-projective (or $M_{2}$ is radical $M_{1}$-projective) and $M_{1}$ and $M_{2}$ are $emph{H}$-cofinitely supplemented, then $M$ is $emph{H}$-cofinitely supplemented
http://bims.iranjournals.ir/article_416_a39509657a78fc90c5d27db44e1ed1d3.pdf
2013-05-15T11:23:20
2019-01-19T11:23:20
325
346
H-supplemented module
H-cofinitely supplemented module
radical-projective module
Y.
Talebi
talebi@umz.ac.ir
true
1
University of Mazandaran, Iran
University of Mazandaran, Iran
University of Mazandaran, Iran
AUTHOR
R.
Tribak
tribak12@yahoo.com
true
2
University of Tetouan
University of Tetouan
University of Tetouan
LEAD_AUTHOR
A.
Moniri Hamzekolaei
a.monirih@umz.ac.ir
true
3
Univeristy of Mazandaran, Iran
Univeristy of Mazandaran, Iran
Univeristy of Mazandaran, Iran
AUTHOR
ORIGINAL_ARTICLE
Hyers-Ulam-Rassias stability of n-Jordan *-homomorphisms on C*-algebras
In this paper, we introduce n-jordan homomorphisms and n-jordan *-homomorphisms and Also investigate the Hyers-Ulam-Rassiasstability of n-jordan *-homomorphisms on C*-algebras.
http://bims.iranjournals.ir/article_417_c380aae386a841b43bbf3cd5bd085049.pdf
2013-05-15T11:23:20
2019-01-19T11:23:20
347
353
Hyers-Ulam-Rassias stability
n-Jordan *-homomorphism
n-jordan homomorphism
C*-algebra
Sh.
Ghaffary Ghaleh
shahram.ghaffary@gmail.com
true
1
Department of Mathematics, Payame Noor University of Zahedan Branch, Zahedan,
Iran
Department of Mathematics, Payame Noor University of Zahedan Branch, Zahedan,
Iran
Department of Mathematics, Payame Noor University of Zahedan Branch, Zahedan,
Iran
LEAD_AUTHOR
Kh.
Ghasemi
khatere.ghasemi@gmail.com
true
2
Department of Mathematics, Payame Noor University of Khash Branch, Khash, Iran
Department of Mathematics, Payame Noor University of Khash Branch, Khash, Iran
Department of Mathematics, Payame Noor University of Khash Branch, Khash, Iran
AUTHOR
ORIGINAL_ARTICLE
Ore extensions of skew $pi$-Armendariz rings
For a ring endomorphism $alpha$ and an $alpha$-derivation $delta$, we introduce a concept, so called skew $pi$-Armendariz ring, that is a generalization of both $pi$-Armendariz rings, and $(alpha,delta)$-compatible skew Armendariz rings. We first observe the basic properties of skew $pi$-Armendariz rings, and extend the class of skew $pi$-Armendariz rings through various ring extensions. We next show that all $(alpha,delta)$-compatible $NI$ rings are skew $pi$-Armendariz, and if a ring $R$ is an $(alpha,delta)$-compatible $2$-$primal$ ring, then the polynomial ring $R[x]$ is skew $pi$-Armendariz.
http://bims.iranjournals.ir/article_315_670f68e3782d06daa57d42c7aaf944da.pdf
2013-05-15T11:23:20
2019-01-19T11:23:20
355
368
skew Armendariz ring
skew $pi$-Armendariz ring
$pi$-Armendariz ring
O.
Lunqun
ouyanglqtxy@163.com
true
1
Department of Mathematics, Hunan University of Science and
Technology,
Xiangtan, Hunan 411201, P.R. China
Department of Mathematics, Hunan University of Science and
Technology,
Xiangtan, Hunan 411201, P.R. China
Department of Mathematics, Hunan University of Science and
Technology,
Xiangtan, Hunan 411201, P.R. China
LEAD_AUTHOR
L.
Jingwang
jwliu64@yohoo.com.cn
true
2
Department of Mathematics, Hunan University of Science and Technology Xiangtan,
Hunan 411201, P. R. China
Department of Mathematics, Hunan University of Science and Technology Xiangtan,
Hunan 411201, P. R. China
Department of Mathematics, Hunan University of Science and Technology Xiangtan,
Hunan 411201, P. R. China
AUTHOR
X.
Yueming
xymls999@126.com
true
3
Department of Mathematics and Applied Mathematics, Huaihua University, Huaihua,
418000, P. R. China
Department of Mathematics and Applied Mathematics, Huaihua University, Huaihua,
418000, P. R. China
Department of Mathematics and Applied Mathematics, Huaihua University, Huaihua,
418000, P. R. China
AUTHOR
ORIGINAL_ARTICLE
On the fixed point theorems in generalized weakly contractive mappings on partial metric spaces
In this paper, we prove a fixed point theorem for a pair of generalized weakly contractive mappings in complete partial metric spaces. The theorems presented are generalizations of very recent fixed point theorems due to Abdeljawad, Karapinar and Tas. To emphasize the very general nature of these results, we illustrate an example.
http://bims.iranjournals.ir/article_344_9cee21f500eec7a4df3245b5b9a8734e.pdf
2013-05-01T11:23:20
2019-01-19T11:23:20
369
381
fixed point theorems
partial metric spaces
weakly contractive mappings
K.
Chi
chidhv@gmail.com
true
1
Vinh University
Vinh University
Vinh University
AUTHOR
E.
Karapinar
erdalkarapinar@yahoo.com
true
2
ATILIM UNIVERSITY
ATILIM UNIVERSITY
ATILIM UNIVERSITY
LEAD_AUTHOR
T.
Thanh
cesurakar@gmail.com
true
3
Vinh University
Vinh University
Vinh University
AUTHOR