Bulletin of the Iranian Mathematical Society
text
article
2015
eng
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
http://bims.iranjournals.ir/article_693_aebe6388c6767ba0888bc8c66b822047.pdf
On the uniqueness theory of algebroid functions in some proper domain
N.
Wu
Department of Mathematics, School of Science, China University of Mining and Technology(Beijing), China
author
Z.
Xuan
Department of General Education, Beijing Union
University, No.97 Bei Si Huan Dong Road, Chaoyang
District, Beijing, 100101, P. R.
China
author
text
article
2015
eng
We consider the uniqueness problem of algebroid functions on an angular domain. Several theorems are established to extend the uniqueness theory of meromorphic functions to algebroid functions.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1315
1326
http://bims.iranjournals.ir/article_694_49ad76602b098c8c8b13f57eb6110143.pdf
An upper bound to the second Hankel functional for the class of gamma-starlike functions
D.
Vamshee Krishna
Department of Mathematics, GIT, GITAM University, Visakh-apatnam-530 045, Andhra Pradesh, India
author
T.
Ramreddy
Department of Mathematics, Kakatiya University, Warangal- 506009, Telangana State, India.
author
text
article
2015
eng
The objective of this paper is to obtain an upper bound to the second Hankel determinant $|a_{2}a_{4}-a_{3}^{2}|$ for the function $f$, belonging to the class of Gamma-starlike functions, using Toeplitz determinants. The result presented here include two known results as their special cases.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1327
1337
http://bims.iranjournals.ir/article_695_5672d8b44702aeecb5427e19d63c856b.pdf
On trees attaining an upper bound on the total domination number
M.
Krzywkowski
Department of Pure and Applied Mathematics, University of Johannesburg, South Africa \newline Research fellow of the Claude Leon Foundation.
Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Poland.
author
text
article
2015
eng
A total dominating set of a graph $G$ is a set $D$ of vertices of $G$ such that every vertex of $G$ has a neighbor in $D$. The total domination number of a graph $G$, denoted by $\gamma_t(G)$, is~the minimum cardinality of a total dominating set of $G$. Chellali and Haynes [Total and paired-domination numbers of a tree, AKCE International ournal of Graphs and Combinatorics 1 (2004), 69--75] established the following upper bound on the total domination number of a tree in terms of the order and the number of support vertices, $\gamma_t(T) \le (n+s)/2$. We characterize all trees attaining this upper bound.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1339
1344
http://bims.iranjournals.ir/article_696_4449325767526406edbfafc623313f35.pdf
Special connections in almost paracontact metric geometry
A. M.
Blaga
Department of Mathematics and Computer Science
West University of Timic{s}oara
Bld. V. P^{a}rvan no. 4, 300223, Timic{s}oara, Romania
author
M.
Crasmareanu
Faculty of Mathematics
University "Al. I. Cuza"
P.O. Box 700506, Iasi, Romania
author
text
article
2015
eng
Two types of properties for linear connections (natural and almost paracontact metric) are discussed in almost paracontact metric geometry with respect to four linear connections: Levi-Civita, canonical (Zamkovoy), Golab and generalized dual. Their relationship is also analyzed with a special view towards their curvature. The particular case of an almost paracosymplectic manifold gives a major simplification in computations since the paracontact form is closed.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1345
1353
http://bims.iranjournals.ir/article_697_3c95645cb316768a942ba47e61ad4352.pdf
On Ads-modules with the SIP
F.
Takil Mutlu
Department of
Mathematics, Anadolu University, 26470, Eskisehir, Turkey
author
text
article
2015
eng
The class of ads modules with the SIP (briefly, $SA$-modules) is studied. Various conditions for a module to be $SA$-module are given. It is proved that for a quasi-continuous module $M$, $M$ is a UC-module if and only if $M$ is an $SA$-module. Also, it is proved that the direct sum of two $SA$-modules as $R$-modules is an $SA$-module when $R$ is the sum of the annihilators of these modules.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1355
1363
http://bims.iranjournals.ir/article_698_13a9b8d0645d896a3aed660bfc22fe59.pdf
Strongly clean triangular matrix rings with endomorphisms
H.
Chen
Department of Mathematics, Hangzhou Normal University, Hangzhou 310034, China
author
H.
Kose
Department of Mathematics, Ahi Evran University, Kirsehir, Turkey
author
Y.
Kurtulmaz
Department of Mathematics, Bilkent University, Ankara, Turkey
author
text
article
2015
eng
A ring $R$ is strongly clean provided that every element in $R$ is the sum of an idempotent and a unit that commutate. Let $T_n(R,\sigma)$ be the skew triangular matrix ring over a local ring $R$ where $\sigma$ is an endomorphism of $R$. We show that $T_2(R,\sigma)$ is strongly clean if and only if for any $a\in 1+J(R), b\in J(R)$, $l_a-r_{\sigma(b)}: R\to R$ is surjective. Further, $T_3(R,\sigma)$ is strongly clean if $l_{a}-r_{\sigma(b)}, l_{a}-r_{\sigma^2(b)}$ and $l_{b}-r_{\sigma(a)}$ are surjective for any $a\in U(R),b\in J(R)$. The necessary condition for $T_3(R,\sigma)$ to be strongly clean is also obtained.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1365
1374
http://bims.iranjournals.ir/article_699_cf47cee6ab49e53faf7620671f4b7476.pdf
Fixed point theorems for $\alpha$-$\psi$-contractive mappings in partially ordered sets and application to ordinary differential equations
M. S.
Asgari
Department of Mathematics, Faculty of Science, Islamic Azad University, Central Tehran Branch, Tehran, Iran
author
Z.
Badehian
Department of Mathematics, Faculty of Science, Islamic Azad University, Central Tehran Branch, Tehran, Iran
author
text
article
2015
eng
In this paper, we introduce $\alpha$-$\psi$-contractive mapping in partially ordered sets and construct fixed point theorems to solve a first-order ordinary differential equation by existence of its lower solution.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1375
1386
http://bims.iranjournals.ir/article_700_0bf7a2d4c715efe5f9af5f8a04bb1945.pdf
Existence and multiplicity of positive solutions for singular Monge-Amp$\rm\grave{e}$re system
F.
Wang
Depatment of Mathematics, College of Science,
Hohai University, Nanjing 210098, China
author
S.
Sun
Depatment of Mathematics, College of Science,
Hohai University, Nanjing 210098, China
author
text
article
2015
eng
Using the fixed point theorem in a cone, the existence and multiplicity of radial convex solutions of singular system of Monge-Amp\`{e}re equations are established.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1387
1399
http://bims.iranjournals.ir/article_701_6291ab56b379c547266237c9b4ff8106.pdf
Some properties for a class of meromorphically multivalent functions with linear operator
X.
Li
Yangtze Univ., Coll. Engn. and Technol., Xueyuan Rd, Jingzhou 434020, Hubei, China
author
L.
Xiong
Engn. and Technol. Coll., Chengdu Univ. of Tech., Xiaoba Rd, Leshan 614000, Sichuan, China
author
text
article
2015
eng
Making use of a linear operator, which is defined here by means of the Hadamard product (or convolution), we define a subclass $\mathcal {T}_{p}(a, c, \gamma, \lambda; h)$ of meromorphically multivalent functions. The main object of this paper is to investigate some important properties for the class. We also derive many results for the Hadamard roducts of functions belonging to the class.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1401
1412
http://bims.iranjournals.ir/article_702_4e58dac3794fc592dd7436fd752cf707.pdf
Some existence results for generalized vector quasi-equilibrium problems
R.
Ahmad
Department of Mathematics, Aligarh Muslim University, Aligarh-202002, India
author
M.
Akram
Department of Mathematics Faculty of Science Islamic University in Madinah, Madinah, KSA
author
text
article
2015
eng
In this paper, we introduce and study a class of generalized vector quasi-equilibrium problem, which includes many vector equilibrium problems, equilibrium problems, vector variational inequalities and variational inequalities as special cases. Using one person game theorems, the concept of escaping sequences and without convexity assumptions, we prove some existence results for generalized vector quasi-equilibrium problem.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1413
1422
http://bims.iranjournals.ir/article_703_1a9a76235fef12f38c4bea85f9de3c92.pdf
Finite groups have even more centralizers
S. M.
Jafarian Amri
Department of Mathematics, Faculty of Sciences, University of Zanjan, P.O. Box 45371-38791, Zanjan, Iran
author
M.
Amiri
Department of Mathematics, Faculty of Sciences, University of Zanjan, P.O. Box 45371-38791, Zanjan, Iran
author
H.
Madadi
Department of Mathematics, Faculty of Sciences, University of Zanjan, P.O. Box 45371-38791, Zanjan, Iran
author
H.
Rostami
Department of Mathematics, Faculty of Sciences, University of Zanjan, P.O. Box 45371-38791, Zanjan, Iran
author
text
article
2015
eng
For a finite group $G$, let $Cent(G)$ denote the set of centralizers of single elements of $G$. In this note we prove that if $|G|\leq \frac{3}{2}|Cent(G)|$ and $G$ is 2-nilpotent, then $G\cong S_3, D_{10}$ or $S_3\times S_3$. This result gives a partial and positive answer to a conjecture raised by A. R. Ashrafi [On finite groups with a given number of centralizers, Algebra Colloq. 7 (2000), no. 2, 139--146].
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1423
1431
http://bims.iranjournals.ir/article_704_da62fe08cf9a7d9a2a6dc962abc95a86.pdf
On the existence of solution for a $k$-dimensional system of three points nabla fractional finite difference equations
Sh.
Rezapour
Department of Mathematics, Azarbaijan Shahid Madani University, Tabriz, Iran
author
S.
Salehi
Department of Mathematics, Azarbaijan Shahid Madani University, Tabriz, Iran
author
text
article
2015
eng
In this paper, we investigate the existence of solution for a k-dimensional system of three points nabla fractional finite difference equations. Also, we present an example to illustrate our result.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1433
1444
http://bims.iranjournals.ir/article_705_33ddec7baae337ee77b901c37b508337.pdf
A note on Volterra and Baire spaces
L. X.
Peng
College of Applied Science, Beijing University of Technology, Beijing 100124, China
author
C.
Yang
College of Applied Science, Beijing University of Technology, Beijing 100124, China
author
text
article
2015
eng
In Proposition 2.6 in (G. Gruenhage, A. Lutzer, Baire and Volterra spaces, \textit{Proc. Amer. Math. Soc.} {128} (2000), no. 10, 3115--3124) a condition that every point of $D$ is $G_\delta$ in $X$ was overlooked. So we proved some conditions by which a Baire space is equivalent to a Volterra space. In this note we show that if $X$ is a monotonically normal $T_1$-space with countable pseudocharacter and $X$ has a $\sigma$-discrete dense subspace $D$, then $X$ is a Baire space if and only if $X$ is Volterra. We show that if $X$ is a metacompact normal sequential $T_1$-space and $X$ has a $\sigma$-closed discrete dense subset, then $X$ is a Baire space if and only if $X$ is Volterra. If $X$ is a generalized ordered (GO) space and has a $\sigma$-closed discrete dense subset, then $X$ is a Baire space if and only if $X$ is Volterra. And also some known results are generalized.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1445
1452
http://bims.iranjournals.ir/article_706_acf9294c55b24f5e0d13a9ac7e8a798c.pdf
A numerical scheme for solving nonlinear backward parabolic problems
A.
Zakeri
Faculty of Mathematics, K. N. Toosi University of Technology, Tehran, Iran
author
Q.
Jannati
Faculty of Mathematics, K. N. Toosi University of Technology, Tehran, Iran
author
A.
Amiri
Faculty of Mathematics, K. N. Toosi University of Technology, Tehran, Iran
author
text
article
2015
eng
In this paper a nonlinear backward parabolic problem in one dimensional space is considered. Using a suitable iterative algorithm, the problem is converted to a linear backward parabolic problem. For the corresponding problem, the backward finite differences method with suitable grid size is applied. It is shown that if the coefficients satisfy some special conditions, this algorithm not only is convergent, but also is conditionally stable. Moreover, it is proved that the estimated values converge to the exact solution of the problem. Al these approaches examined in some numerical examples. corresponding theorems for the convergency and stability of the solution are studied.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1453
1464
http://bims.iranjournals.ir/article_707_910e025082adb46d6de4d47534795eeb.pdf
On centralizers of prime rings with involution
S.
Ali
Department of mathematics, Faculty of science & Arts-Rabigh, King Abdulaziz University, Jaddeh 21589, Saudi Arabia
author
N. A.
Dar
Department of mathematics, Aligarh Muslim University, Aligarh-202002, Aligarh, India
author
text
article
2015
eng
Let $R$ be a ring with involution $*$. An additive mapping $T:R\to R$ is called a left(respectively right) centralizer if $T(xy)=T(x)y$ (respectively $T(xy)=xT(y)$) for all $x,y\in R$. The purpose of this paper is to examine the commutativity of prime rings with involution satisfying certain identities involving left centralizers.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1465
1475
http://bims.iranjournals.ir/article_708_51e848e67053d7d6aa517c850476d9a6.pdf
The fibering map approach to a quasilinear degenerate p(x)-Laplacian equation
S.
Saiedinezhad
Department of Mathematics, Iran University of Science and Technology, Tehran, Iran
author
M. B.
Ghaemi
Department of Mathematics, Iran University of Science and Technology, Tehran, Iran
author
text
article
2015
eng
By considering a degenerate $p(x)-$Laplacian equation, a generalized compact embedding in weighted variable exponent Sobolev space is presented. Multiplicity of positive solutions are discussed by applying fibering map approach for the corresponding Nehari manifold.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1477
1492
http://bims.iranjournals.ir/article_709_757882303882b6327cb3554affd5dfed.pdf
Groups with one conjugacy class of non-normal subgroups - a short proof
H.
Mousavi
Department of Mathematics,
University of Tabriz,
P.O.Box 51666-17766, Tabriz, Iran
author
text
article
2015
eng
For a finite group $G$ let $nu(G)$ denote the number of conjugacy classes of non-normal subgroups of $G$. We give a short proof of a theorem of Brandl, which classifies finite groups with $nu(G)=1$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1493
1495
http://bims.iranjournals.ir/article_710_9d8908c7ccaafc905227f39a53234514.pdf
Automatic continuity of almost multiplicative maps between Frechet algebras
T.
Ghasemi Honary
Department of
Mathematics, Kharazmi University, 1561836314, Tehran, Iran
author
M.
Omidi
Department of
Mathematics, Kharazmi University, 1561836314, Tehran, Iran
author
A. H.
Sanatpour
Department of Mathematics, Kharazmi University, 1561836314, Tehran, Iran
author
text
article
2015
eng
For Fr$acute{mathbf{text{e}}}$chet algebras $(A, (p_n))$ and $(B, (q_n))$, a linear map $T:Arightarrow B$ is textit{almost multiplicative} with respect to $(p_n)$ and $(q_n)$, if there exists $varepsilongeq 0$ such that $q_n(Tab - Ta Tb)leq varepsilon p_n(a) p_n(b),$ for all $n in mathbb{N}$, $a, b in A$, and it is called textit{weakly almost multiplicative} with respect to $(p_n)$ and $(q_n)$, if there exists $varepsilongeq 0$ such that for every $k in mathbb{N}$, there exists $n(k) in mathbb{N}$, satisfying the inequality $q_k(Tab - Ta Tb)leq varepsilon p_{n(k)}(a) p_{n(k)}(b),$ for all $a, b in A$. We investigate the automatic continuity of (weakly) almost multiplicative maps between certain classes of Fr$acute{mathbf{text{e}}}$chet algebras, such as Banach algebras and Fr$acute{mathbf{text{e}}}$chet $Q$-algebras. We also obtain some results on the automatic continuity of dense range (weakly) almost multiplicative maps between Fr$acute{mathbf{text{e}}}$chet algebras.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1497
1509
http://bims.iranjournals.ir/article_711_6fbfa2598e04c4a02cb5f3b4852f8f07.pdf
The Libera operator on Dirichlet spaces
G.
Bao
Department of Mathematics, Shantou University, Shantou 515063, China
author
J.
Yang
Department of
Mathematics, Shanghai Maritime University, Shanghai 201306, China
author
text
article
2015
eng
In this paper, we consider the boundedness of the Libera operator on Dirichlet spaces in terms of the Schur test. Moreover, we get its point spectrum and norm.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1511
1517
http://bims.iranjournals.ir/article_712_f00be65aabf0d408421269ce1742d9f9.pdf
On the modified iterative methods for $M$-matrix linear systems
F.
Panjeh Ali Beik
Department of Mathematics, Vali-e-Asr University of Rafsanjan, P.O. Box 518, Rafsanjan, Iran
author
N.
Nasseri Shams
Department of Mathematics, Vali-e-Asr University of Rafsanjan, P.O. Box 518, Rafsanjan, Iran
author
text
article
2015
eng
This paper deals with scrutinizing the convergence properties of iterative methods to solve linear system of equations. Recently, several types of the preconditioners have been applied for ameliorating the rate of convergence of the Accelerated Overrelaxation (AOR) method. In this paper, we study the applicability of a general class of the preconditioned iterative methods under certain conditions. More precisely, it is demonstrated that the preconditioned Mixed-Type Splitting (MTS) iterative methods can surpass the preconditioned AOR iterative methods for an entirely general class of preconditioners handled by Wang and Song [J. Comput. Appl. Math. 226 (2009), no. 1, 114--124]. Finally some numerical results are elaborated which confirm the validity of the established results.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
41
v.
6
no.
2015
1519
1535
http://bims.iranjournals.ir/article_713_ca10664f5ca2128219136cbb3a3bbeb4.pdf