eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1559
1570
1034
Caratheodory dimension for observers
M.R. Molaei
mrmolaei@mail.uk.ac.ir
1
Y. Sayyari
ysayyari@gmail.com
2
Department of Pure Mathematics, Faculty of Mathematics and Computer, Shahid Bahonar University of Kerman, Kerman, Iran.
Department of Pure Mathematics, Faculty of Mathematics and Computer, Shahid Bahonar University of Kerman, Kerman, Iran.
In this essay we introduce and study the notion of dimension for observers via Caratheodory structures and relative probability measures. We show that the dimension as a three variables function is an increasing function on observers, and decreasing function on the cuts of an observer. We find observers with arbitrary non-negative dimensions. We show that Caratheodory dimension for observers is an invariant object under conjugate relations. Caratheodory dimension as a mapping, for multi-dimensional observers is considered. News spread is modeled via multi-dimensional observers.
http://bims.iranjournals.ir/article_1034_60a101abff7a9ba09724f8efa7ac7b21.pdf
Caratheodory structure
observer
news spread
Hausdorff dimension
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1571
1583
1040
On three-dimensional $N(k)$-paracontact metric manifolds and Ricci solitons
U.C. De
uc_de@yahoo.com
1
S. Deshmukh
shariefd@ksu.edu.sa
2
K. Mandal
krishanu.mandal013@gmail.com
3
Department of Pure Mathematics, University of Calcutta, 35, Ballygunge Circular Road, Kol- 700019, West Bengal, India.
Department of Mathematics, College of Science, King saud University, P.O. Box-2455, Riyadh-11451, Saudi Arabia.
Department of Pure Mathematics, University of Calcutta, 35, Ballygunge Circular Road, Kol- 700019, West Bengal, India.
The aim of this paper is to characterize $3$-dimensional $N(k)$-paracontact metric manifolds satisfying certain curvature conditions. We prove that a $3$-dimensional $N(k)$-paracontact metric manifold $M$ admits a Ricci soliton whose potential vector field is the Reeb vector field $xi$ if and only if the manifold is a paraSasaki-Einstein manifold. Several consequences of this result are discussed. Finally, an illustrative example is constructed.
http://bims.iranjournals.ir/article_1040_a446023e2cc7956949c8c04a16793c63.pdf
Ricci semisymmetric
cyclic parallel Ricci tensor
$\eta$-parallel Ricci tensor
Ricci soliton
Einstein manifold
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1585
1600
1038
Decay estimates of solutions to the IBq equation
Y. Zhang
yzzhangmath@126.com
1
P. Li
782133407@qq.com
2
School of Mathematics and Statistics, North China University of Water Resources and Electric Power, Zhengzhou 450011, China.
School of Mathematics and Statistics, North China University of Water Resources and Electric Power, Zhengzhou 450011, China.
In this paper we focus on the Cauchy problem for the generalized IBq equation with damped term in $n$-dimensional space. We establish the global existence and decay estimates of solution with $L^q(1\leq q\leq 2)$ initial value, provided that the initial value is suitably small. Moreover, we also show that the solution is asymptotic to the solution $u_L$ to the corresponding linear equation as time tends to infinity. Finally, asymptotic profile of the solution $u_L$ to the linearized problem is also discussed.
http://bims.iranjournals.ir/article_1038_738b44c2e71a0ee521ae3bc6352b4008.pdf
IBq equation
global existence
decay estimates
asymptotic profile
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1601
1619
1035
Functional identities of degree 2 in CSL algebras
D. Han
lishe@hpu.edu.cn
1
School of Mathematics and Information Science, Henan Polytechnic University, Jiaozuo, 454000, P.R. China.
Let $\mathscr{L}$ be a commutative subspace lattice generated by finite many commuting independent nests on a complex separable Hilbert space $\mathbf{H}$ with ${\rm dim}\hspace{2pt}\mathbf{H}\geq 3$, ${\rm Alg}\mathscr{L}$ the CSL algebra associated with $\mathscr{L}$ and $\mathscr{M}$ be an algebra containing ${\rm Alg}\mathscr{L}$. This article is aimed at describing the form of additive mapppings $F_1, F_2, G_1, G_2\colon {\rm Alg}\mathscr{L}\longrightarrow \mathscr{M}$ satisfying functional identity $F_1(X)Y+F_2(Y)X+XG_2(Y)+YG_1(X)=0$ for all $X, Y\in {\rm Alg}\mathscr{L}$. As an application generalized inner biderivations and commuting additive mappings are determined.
http://bims.iranjournals.ir/article_1035_743a4e08ff10b2e3cd9fa16b23cc1eae.pdf
Functional identity
CSL algebra
generalized inner biderivation
commuting mapping
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1621
1628
1042
The length of Artinian modules with countable Noetherian dimension
M. Davoudian
m.davoudian@scu.ac.ir
1
O. Ghayour
o.ghayour@yahoo.com
2
Department of Mathematics, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Department of Mathematics, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
It is shown that if $M$ is an Artinian module over a ring $R$, then $M$ has Noetherian dimension $\alpha $, where $\alpha $ is a countable ordinal number, if and only if $\omega ^{\alpha }+2\leq \it{l}(M)\leq \omega ^{\alpha +1}$, where $ \it{l}(M)$ is the length of $M$, $i.e.,$ the least ordinal number such that the interval $[0, \ \it{l}(M))$ cannot be embedded in the lattice of all submodules of $M$.
http://bims.iranjournals.ir/article_1042_3a9a8677dfa67377a62a97351e3a6e04.pdf
Artinian module
Noetherian dimension
atomic module
the length of an R-module
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1629
1644
1044
On derivations and biderivations of trivial extensions and triangular matrix rings
N.M. Ghosseiri
mnghosseiri@yahoo.com
1
Department of Mathematics, University of Kurdistan, P.O. Box 416, Sanandaj, Iran.
Triangular matrix rings are examples of trivial extensions. In this article we determine the structure of derivations and biderivations of the trivial extensions, and thereby we describe the derivations and biderivations of the upper triangular matrix rings. Some related results are also obtained.
http://bims.iranjournals.ir/article_1044_21e6b15378858865b24096a56c02831e.pdf
Trivial extension
triangular matrix ring
derivation
biderivation
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1645
1655
1045
Two-geodesic transitive graphs of prime power order
W. Jin
jinweipei82@163.com
1
School of Statistics, Jiangxi University of Finance and Economics, Nanchang, Jiangxi, 330013, P.R. China
In a non-complete graph $\Gamma$, a vertex triple $(u,v,w)$ with $v$ adjacent to both $u$ and $w$ is called a $2$-geodesic if $uneq w$ and $u,w$ are not adjacent. The graph $\Gamma$ is said to be $2$-geodesic transitive if its automorphism group is transitive on arcs, and also on 2-geodesics. We first produce a reduction theorem for the family of $2$-geodesic transitive graphs of prime power order. Next, we classify such graphs which are also vertex quasiprimitive.
http://bims.iranjournals.ir/article_1045_dfcf1e1367b8d9455343433f1e659a9c.pdf
2-geodesic transitive graph
2-arc transitive graph
automorphism group
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1657
1669
1049
Stability of F-biharmonic maps
S.M. Kazemi Torbaghan
mehdikazemi@aut.ac.ir
1
M.M. Rezaii
mmreza@aut.ac.ir
2
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran.
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran.
This paper studies some properties of F-biharmonic maps between Riemannian manifolds. By considering the first variation formula of the F-bienergy functional, F-biharmonicity of conformal maps are investigated. Moreover, the second variation formula for F-biharmonic maps is obtained. As an application, instability and nonexistence theorems for F-biharmonic maps are given.
http://bims.iranjournals.ir/article_1049_6c770288ef08175535eb53634c6ca3a0.pdf
Biharmonic maps
F-biharmonic maps
conformal maps
stability
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1671
1677
1052
Gorenstein hereditary rings with respect to a semidualizing module
G. Zhao
gqzhao@hdu.edu.cn
1
B. Zhang
bzhang1980@126.com
2
Department of Mathematics, Hangzhou Dianzi University, Hangzhou, 310018, P.R. China.
School of Mathematics and Information Science, Henan Polytechnic University, Jiaozuo, 454000, P.R. China.
Let $C$ be a semidualizing module. We first investigate the properties of finitely generated $G_C$-projective modules. Then, relative to $C$, we introduce and study the rings over which every submodule of a projective (flat) module is $G_C$-projective (flat), which we call $C$-Gorenstein (semi)hereditary rings. It is proved that every $C$-Gorenstein hereditary ring is both coherent and $C$-Gorenstein semihereditary.
http://bims.iranjournals.ir/article_1052_a5c3f63a6c7c776ea5aa5f168bb1c109.pdf
Semidualizing module
$G_C$-projective module
$G_C$-flat module
$G_C$-(semi)hereditary ring
coherent ring
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1679
1694
1053
Duality for vector equilibrium problems with constraints
N.L.H. Anh
nlhanh@hcmus.edu.vn
1
Department of Optimization and System Theory, University of Science, Vietnam National University Hochiminh City, 227 Nguyen Van Cu, District 5, Hochiminh City, Vietnam.
In the paper, we study duality for vector equilibrium problems using a concept of generalized convexity in dealing with the quasi-relative interior. Then, their applications to optimality conditions for quasi-relative efficient solutions are obtained. Our results are extensions of several existing ones in the literature when the ordering cones in both the objective space and the constraint space have possibly empty interior.
http://bims.iranjournals.ir/article_1053_eba0fe1a292ed8178692f970c5e4725a.pdf
Equilibrium problem
duality
optimality conditions
quasi-relative efficient solution
generalized subconvexlikeness
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1695
1698
1054
An upper bound for the regularity of powers of edge ideals
M. Moghimian
math_moghimi@yahoo.com
1
Department of Mathematics, Science and Research Branch, Islamic Azad University (IAU), Tehran, Iran.
A recent result due to Ha and Van Tuyl proved that the Castelnuovo-Mumford regularity of the quotient ring $R/I(G)$ is at most matching number of $G$, denoted by match$(G)$. In this paper, we provide a generalization of this result for powers of edge ideals. More precisely, we show that for every graph $G$ and every $s\geq 1$, $${\rm reg}( R/ I(G)^{s})\leq (2s-1) |E(G)|^{s-1} {\rm match}(G).$$
http://bims.iranjournals.ir/article_1054_da3531e9ece50748643698a60817cad6.pdf
Edge ideal
Castelnuovo-Mumford regularity
matching number
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1699
1707
1056
Properties of matrices with numerical ranges in a sector
D. Zhang
zhangdengpeng@sina.cn
1
L. Hou
houlei@staff.shu.edu.cn
2
L. Ma
amandalulu918@163.com
3
Department of Mathematics, Shanghai University, Shanghai 200444, China.
Department of Mathematics, Shanghai University, Shanghai 200444, China.
Department of Mathematics, Shanghai University, Shanghai 200444, China.
Let $(A)$ be a complex $(n\times n)$ matrix and assume that the numerical range of $(A)$ lies in the set of a sector of half angle $(\alpha)$ denoted by $(S_{\alpha})$. We prove the numerical ranges of the conjugate, inverse and Schur complement of any order of $(A)$ are in the same $(S_{\alpha})$.The eigenvalues of some kinds of matrix product and numerical ranges of hadmard product, star-congruent matrix and unitary matrix of polar decompostion are also included in the same sector. Furthermore, we extend some inequalities about eigenvalues and singular values and the linear fractional maps to this class of matrices.
http://bims.iranjournals.ir/article_1056_b52b59d9cddfb9e022bc31ed6322b513.pdf
Numerical ranges
sector
positive definite
Toeplitz decomposition
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1709
1721
1057
On nuclei of sup-$\Sigma$-algebras
X. Zhang
xzhang@m.scnu.edu.cn
1
Y. Zhou
secret9288@163.com
2
School of Mathematical Sciences, South China Normal University, 510631 Guangzhou, China.
School of Mathematical Sciences, South China Normal University, 510631 Guangzhou, China.
In this paper, algebraic investigations on sup-$\Sigma$-algebras are presented. A representation theorem for sup-$\Sigma$-algebras in terms of nuclei and quotients is obtained. Consequently, the relationship between the congruence lattice of a sup-$\Sigma$-algebra and the lattice of its nuclei is fully developed.
http://bims.iranjournals.ir/article_1057_99be559b2c84987c08fb22e247fad759.pdf
Sup-$\Sigma$-algebra
nucleus
congruence
quotient
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1723
1737
1059
High-accuracy alternating segment explicit-implicit method for the fourth-order heat equation
G. Guo
guogeyang2000@sina.com
1
S. Lü
lsj@buaa.edu.cn
2
School of Mathematics and Systems Science, Beijing University of Aeronautics and Astronautics, Beijing 100191, PR China.
School of Mathematics and Systems Science, Beijing University of Aeronautics and Astronautics, Beijing 100191, China.
Based on a group of new Saul’yev type asymmetric difference schemes constructed by author, a high-order, unconditionally stable and parallel alternating segment explicit-implicit method for the numerical solution of the fourth-order heat equation is derived in this paper. The truncation error is fourth-order in space, which is much more accurate than the known alternating segment explicit-implicit methods. Numerical simulations are performed to show the effectiveness of thepresent method that are in preference to the prior methods.
http://bims.iranjournals.ir/article_1059_993ed41f72e1186dd00628a34c963615.pdf
Fourth-order heat equation
alternating segment explicit-implicit method
high accuracy
parallel computation
unconditional stability
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1739
1749
1060
Applications of convolution and subordination to certain $p$-valent functions
S. Hussain
saqib_math@yahoo.com
1
J. Sokół
jsokol@prz.edu.pl
2
U. Farooq
umi_am11@yahoo.com
3
M. Darus
maslina@ukm.edu.my
4
T. Mahmood
tahirbakhat@yahoo.com
5
Department of Mathematics, COMSATS Institute of Information Technology Abbotabad, Pakistan.
Department of Mathematics, Institute of Mathematics, University of Rzeszow, ul. Rejtana 16A, 35-310 Rzeszow, Poland.
Department of Mathematics, Government Postgraduate College, Abbottabad, Pakistan.
School of Mathematical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia.
Department of Mathematics and Statistics, International Islamic University Islamabad, Pakistan.
In this paper we considered some new classes of multivalent functions by using Aouf-Silverman-Srivastava operator and derived some important results using convolution and subordination technique. This new class is an extension of a class which introduced before.
http://bims.iranjournals.ir/article_1060_2c675a7b7dd48d7b233b76c37b11a172.pdf
Multivalent function
convolution
Subordination
linear operator
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1751
1767
1065
Hölder continuity of solution maps to a parametric weak vector equilibrium problem
P. Preechasilp
preechasilpp@gmail.com
1
R. wangkeeree
rabianw@nu.ac.th
2
Program in Mathematics, Pibulsongkram Rajabhat University, Phitsanulok, Thailand.
Department of Mathematics,Naresuan University, Phitsanulok, Thailand.
In this paper, by using a new concept of strong convexity, we obtain sufficient conditions for Holder continuity of the solution mapping for a parametric weak vector equilibrium problem in the case where the solution mapping is a general set-valued one. Without strong monotonicity assumptions, the Holder continuity for solution maps to parametric weak vector optimization problems is discussed.
http://bims.iranjournals.ir/article_1065_2e8c10b5f887027ce679d1615238281e.pdf
Vector equilibrium problem
solution mapping
Hölder continuity
linear scalarization
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1769
1779
1062
Hyperbolic surfaces of $L_1$-2-type
P. Lucas
plucas@um.es
1
H.F. Ramírez-Ospina
hframirezo@unal.edu.co
2
Departamento de Matemáticas, Facultad de Matemáticas, Universidad de Murcia, 30100 Murcia, Spain.
Departamento de Matemáticas, Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá DC, Colombia.
In this paper, we show that an $L_1$-2-type surface in the three-dimensional hyperbolic space $H^3\subset R^4_1$ either is an open piece of a standard Riemannian product $ H^1(-\sqrt{1+r^2})\times S^{1}(r)$, or it has non constant mean curvature, non constant Gaussian curvature, and non constant principal curvatures.
http://bims.iranjournals.ir/article_1062_5af9f5b2ebe4719b4560a0e48f304949.pdf
Hyperbolic surface
Cheng-Yau operator
$L_1$-finite-type surface
$L_1$-biharmonic surface
Newton transformation
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1781
1790
1063
The second dual of strongly zero-product preserving maps
A.R. Khoddami
khoddami.alireza@shahroodut.ac.ir
1
Faculty of Mathematical Sciences, Shahrood University of Technology, P.O. Box 3619995161-316, Shahrood, Iran.
The notion of strongly Lie zero-product preserving maps on normed algebras as a generalization of Lie zero-product preserving maps are defined. We give a necessary and sufficient condition from which a linear map between normed algebras to be strongly Lie zero-product preserving. Also some hereditary properties of strongly Lie zero-product preserving maps are presented. Finally the second dual of a strongly zero-product, strongly Jordan zero-product and strongly Lie zero-product preserving map on a certain class of normed algebras are investigated.
http://bims.iranjournals.ir/article_1063_7b8628e66b977698b444316e36a92e54.pdf
Strongly zero-product preserving map
strongly Jordan zero-product preserving map
strongly Lie zero-product preserving map
Arens regular
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1791
1800
1064
Classification of solvable groups with a given property
M. Rezaei
mehdrezaei@gmail.com
1
Z. Foruzanfar
zforouzanfar@gmail.com
2
Department of Mathematics, Buein Zahra Technical University, Buein Zahra, Qazvin, Iran.
Department of Mathematics, Buein Zahra Technical University, Buein Zahra, Qazvin, Iran.
In this paper we classify all finite solvable groups satisfying the following property P5: their orders of representatives are set-wise relatively prime for any 5 distinct non-central conjugacy classes.
http://bims.iranjournals.ir/article_1064_5e25c91a6bdc31bbd41bfb454b5334ef.pdf
Frobenius group
Conjugacy classes
graph
order
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1801
1810
1061
The graph of equivalence classes and Isoclinism of groups
R. Rezaei
ras_rezaei@yahoo.com
1
M. Varmazyar
m_varmazyar61@yahoo.com
2
Department of Mathematics, Faculty of Mathematical Sciences, Malayer University, Malayer, Iran.
Department of Mathematics, Faculty of Mathematical Sciences, Malayer University, Malayer, Iran.
Let $G$ be a non-abelian group and let $\Gamma(G)$ be the non-commuting graph of $G$. In this paper we define an equivalence relation $\sim$ on the set of $V(\Gamma(G))=G\setminus Z(G)$ by taking $x\sim y$ if and only if $N(x)=N(y)$, where $ N(x)=\{u\in G \ | \ x \textrm{ and } u \textrm{ are adjacent in }\Gamma(G)\}$ is the open neighborhood of $x$ in $\Gamma(G)$. We introduce a new graph determined by equivalence classes of non-central elements of $G$, denoted $\Gamma_E(G)$, as the graph whose vertices are $\{[x] \ | \ x \in G\setminus Z(G)\}$ and join two distinct vertices $[x]$ and $[y]$, whenever $[x,y]\neq 1$. We prove that group $G$ is AC-group if and only if $\Gamma_E(G)$ is complete graph. Among other results, we show that the graphs of equivalence classes of non-commuting graph associated with two isoclinic groups are isomorphic.
http://bims.iranjournals.ir/article_1061_2b7cba5aa6cdb3872025474bf8edf9fb.pdf
Non-commuting graph
graph of equivalence classes
Isoclinism
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1811
1820
1066
Defining relations of a group $\Gamma= G^{3,4}(2,Z)$ and its action on real quadratic field
M. Ashiq
m.ashiq@mcs.edu.pk
1
T. Imran
tahirimran_78@yahoo.com
2
M. A. Zaighum
asadzaighum@gmail.com
3
National University of Sciences and Technology, MCS Campus, Rawalpindi,\ Pakistan.
Department of mathematics and statistics, Riphah International University, Islamabad, Pakistan.
Department of Basic Sciences Riphah International University Islamabad, Pakistan.
In this paper, we have shown that the coset diagrams for the action of a linear-fractional group $\Gamma$ generated by the linear-fractional transformations $r:z\rightarrow \frac{z-1}{z}$ and $s:z\rightarrow \frac{-1}{2(z+1)}$ on the rational projective line is connected and transitive. By using coset diagrams, we have shown that $r^{3}=s^{4}=1$ are defining relations for $\Gamma$. Furthermore, we have studied some important results for the action of group $\Gamma$ on real quadratic field $Q(\sqrt{n})$. Also, we have classified all the ambiguous numbers in the orbit.
http://bims.iranjournals.ir/article_1066_6cbc8ab9f3f6e93ee2c811ce21ce6a68.pdf
Coset diagrams
modular group
linear-fractional transformations
real quadratic field
ambiguous numbers
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
1999-11-30
43
6
1821
1835
1067
Entropy of a semigroup of maps from a set-valued view
B. Hou
houbz@jlu.edu.cn
1
X. Wang
chengjiuyouxiu@sina.com
2
College of Mathematics, Jilin university, 130012, Changchun, P. R. China.
College of Mathematics, Jilin university, 130012, Changchun, P. R. China.
In this paper, we introduce a new entropy-like invariant, named Hausdorff metric entropy, for finitely generated semigroups acting on compact metric spaces from a set-valued view and study its properties. We establish the relation between Hausdorff metric entropy and topological entropy of a semigroup defined by Bis. Some examples with positive or zero Hausdorff metric entropy are given. Moreover, some notions of chaos are also well generalized for finitely generated semigroups from a set-valued view.
http://bims.iranjournals.ir/article_1067_479aa58a4bb53422d87b5956ff62afe4.pdf
Topological entropy
semigroups
entropy-like invariants
Hausdorff metric
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1837
1854
1068
Initial coefficients of starlike functions with real coefficients
S. Kumar
sushilkumar16n@gmail.com
1
V. Ravichandran
vravi68@gmail.com
2
S. Verma
jmdsv.maths@gmail.com
3
Bharati Vidyapeeth's College of Engineering, Delhi--110063, India.
Department of Mathematics, University of Delhi Delhi--110 007, India.
Department of Mathematics, University of Delhi, Delhi--110 007, India.
The sharp bounds for the third and fourth coefficients of Ma-Minda starlike functions having fixed second coefficient are determined. These results are proved by using certain constraint coefficient problem for functions with positive real part whose coefficients are real and the first coefficient is kept fixed. Analogous results are obtained for a general class of close-to-convex functions
http://bims.iranjournals.ir/article_1068_2d1a93d22ef0d7481f165dcb3825c786.pdf
Coefficient estimates
starlike functions
close to convex functions
functions with positive real part
real coefficient
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1855
1866
1069
Classifying pentavalnet symmetric graphs of order $24p$
B. Ling
bolinggxu@163.com
1
School of Mathematics and Computer Sciences, Yunnan Minzu University, Kunming, Yunnan 650504, P.R. China.
A graph is said to be symmetric if its automorphism group is transitive on its arcs. A complete classification is given of pentavalent symmetric graphs of order 24p for each prime p. It is shown that a connected pentavalent symmetric graph of order 24p exists if and only if p=2, 3, 5, 11 or 17, and up to isomorphism, there are only eleven such graphs.
http://bims.iranjournals.ir/article_1069_e6c795ff2cc2616cd81138a8139b0332.pdf
Symmetric graph
normal quotient
automorphism group
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1867
1888
1244
A weak approximation for the Extrema's distributions of Levy processes
A.T. Payandeh Najafabadi
amirtpayandeh@sbu.ac.ir
1
D.Z. Kucerovsky
dkucerov@unb.ca
2
Department of Mathematical Sciences, Shahid Beheshti University, G.C. Evin, 1983963113, Tehran, Iran.
Department of Mathematics and Statistics, University of New Brunswick, Fredericton, N.B. Canada E3B 5A3.
Suppose that $X_{t}$ is a one-dimensional and real-valued L\'evy process started from $X_0=0$, which ({\bf 1}) its nonnegative jumps measure $\nu$ satisfying $\int_{\Bbb R}\min\{1,x^2\}\nu(dx)<\infty$ and ({\bf 2}) its stopping time $\tau(q)$ is either a geometric or an exponential distribution with parameter $q$ independent of $X_t$ and $\tau(0)=\infty.$ This article employs the Wiener-Hopf Factorization (WHF) to find, an $L^{p^*}({\Bbb R})$ (where $1/{p^*}+1/p=1$ and $1<p\leq2$), approximation for the extrema's distributions of $X_{t}.$ Approximating the finite (infinite)-time ruin probability as a direct application of our findings has been given. Estimation bounds, for such approximation method, along with two approximation procedures and several examples are explored.
http://bims.iranjournals.ir/article_1244_7733deed4511081e9bceedc681ecc11b.pdf
Levy processes
positive-definite function
extrema's distributions
the Fourier transform
the Hilbert transform
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1889
1903
1070
Existence of positive solutions for a second-order p-Laplacian impulsive boundary value problem on time scales
F. Tokmak Fen
fatma.tokmakk@gmail.com
1
I.Y. Karaca
ilkay.karaca@ege.edu.tr
2
Department of Mathematics, Gazi University, Teknikokullar, 06500 Ankara, Turkey.
Department of Mathematics, Ege University, Bornova, 35100 Izmir, Turkey.
In this paper, we investigate the existence of positive solutions for a second-order multipoint p-Laplacian impulsive boundary value problem on time scales. Using a new fixed point theorem in a cone, sufficient conditions for the existence of at least three positive solutions are established. An illustrative example is also presented.
http://bims.iranjournals.ir/article_1070_da5504c917fa9b3f5a2cd16c41f2ca5a.pdf
Impulsive boundary value problems
p-Laplacian
positive solutions
fixed point theorem
Time scales
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1905
1912
1073
When is the ring of real measurable functions a hereditary ring?
H. Hejazipour
h.hejazipoor@gmail.com
1
A. R. Naghipour
naghipourar@yahoo.com
2
Department of Mathematical Sciences, Shahrekord University, P.O. Box 115, Shahrekord, Iran.
Department of Mathematical Sciences, Shahrekord University, P.O. Box 115, Shahrekord, Iran.
Let $M(X, \mathcal{A}, \mu)$ be the ring of real-valued measurable functions on a measure space $(X, \mathcal{A}, \mu)$. In this paper, we characterize the maximal ideals in the rings of real measurable functions and as a consequence, we determine when $M(X, \mathcal{A}, \mu)$ is a hereditary ring.
http://bims.iranjournals.ir/article_1073_1eb98851b6536cbd289da1c626d55f8d.pdf
Measurable functions
hereditary rings
projective prime ideals
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1913
1924
1074
Subdirectly irreducible acts over some semigroups
Gh. Moghaddasi
r.moghadasi@hsu.ac.ir
1
M. Mahmoudi
m-mahmoudi@sbu.ac.ir
2
Department of Mathematics, Hakim Sabzevari University, Sabzevar, Iran.
Department of Mathematics, Shahid Beheshti University, Tehran, Iran.
In this paper, we characterize and find the number of subdirectly irreducible acts over some classes of semigroups, such as zero semigroups, right zero semigroups and strong chain of left zero semigroups.
http://bims.iranjournals.ir/article_1074_23345385ea8c6ec1307ceb3d81b2ed2b.pdf
Subdirectly irreducible
chain of semigroups
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1925
1937
1075
The lower bound for the number of 1-factors in generalized Petersen graphs
H. Ren
hren@math.ecnu.edu.cn
1
C. Yang
yangchaomath0524@163.com
2
J. Wang
jlwang@math.ecnu.edu.cn
3
Department of Mathematics, East China Normal University, Shanghai, 200241, P.R. China
School of Mathematics, Physics and Statistics, Shanghai University of Engineering Science, Shanghai, 201620, P.R. China.
Department of Mathematics, East China Normal University, Shanghai, 200241, P.R. China.
In this paper, we investigate the number of 1-factors of a generalized Petersen graph $P(N,k)$ and get a lower bound for the number of 1-factors of $P(N,k)$ as $k$ is odd, which shows that the number of 1-factors of $P(N,k)$ is exponential in this case and confirms a conjecture due to Lovász and Plummer (Ann. New York Acad. Sci. 576(2006), no. 1, 389-398).
http://bims.iranjournals.ir/article_1075_cf616b56426d01c35cd3041b4df264ed.pdf
Generalized Petersen graphs
matching
1-factors
Fibonacci number
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1939
1955
1076
Composition of resolvents and quasi-nonexpansive multivalued mappings in Hadamared spaces
G. Zamani Eskandani
g_eskandani@yahoo.com
1
S. Azarmi
s.azarmi2008@gmail.com
2
M. Eslamian
mhmdeslamian@gmail.com
3
Department of Pure Mathematics, Faculty of Mathematical Sciences, University of Tabriz, Tabriz, Iran.
Department of Pure Mathematics, Faculty of Mathematical Sciences, University of Tabriz, Tabriz, Iran.
Department of Mathematics, University of Science and Technology of Mazandaran, P.O. Box 48518-78195, Behshahr, Iran.
The proximal point algorithm, which is a well-known tool for finding minima of convex functions, is generalized from the classical Hilbert space framework into a nonlinear setting, namely, geodesic metric spaces of nonpositive curvature. In this paper we propose an iterative algorithm for finding the common element of the minimizers of a finite family of convex functions and the common fixed points of a finite family of quasi-nonexpansive multivalued mappings in Hadamard spaces.
http://bims.iranjournals.ir/article_1076_669539101764946143d80ea1280ca7a4.pdf
Proximal point algorithm
$CAT(0)$ spaces
Nonexpansive multivalued mappings
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1957
1968
1077
A hybrid mean value involving a new Gauss sums and Dedekind sums
X.X. Li
lxx20072012@163.com
1
W.P. Zhang
wpzhang@nwu.edu.cn
2
School of Mathematics, Northwest University, Xi'an, Shaanxi, 710127, P.R. China.
School of Mathematics, Northwest University, Xi'an, Shaanxi, 710127, P.R. China.
In this paper, we introduce a new sum analogous to Gauss sum, then we use the properties of the classical Gauss sums and analytic method to study the hybrid mean value problem involving this new sums and Dedekind sums, and give an interesting identity for it.
http://bims.iranjournals.ir/article_1077_2158a37858112c93483a006a0f583088.pdf
A new Gauss sums
Dedekind sums
hybrid mean value
identity
analytic method
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1969
1987
1078
Semi-Rothberger and related spaces
A. Sabah
amaniussabah@gmail.com
1
M. Khan
moiz@comsats.edu.pk
2
Department of Mathematics, COMSATS Institute of Information Technology, Chack Shahzad, Park Road, Islamabad 45550, Pakistan.
Department of Mathematics, COMSATS Institute of Information Technology, Chack Shahzad, Park Road, Islamabad 45550, Pakistan.
In this paper our focus is to study certain covering properties in topological spaces by using semi-open covers. A part of this article deals with Rothberger-type covering properties. The notions of s-Rothberger, almost s-Rothberger, star s-Rothberger, almost star s-Rothberger, strongly star s-Rothberger spaces are defined and corresponding properties are investigated.
http://bims.iranjournals.ir/article_1078_9fad6d520d7acfc75e636817ab29dff9.pdf
Semi-open set, (star) semi-compact space
semi-Lindelöf space
s-Rothberger space
star s-Rothberger space
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
1989
2016
1079
A descent method for explicit computations on curves
K. Filom
filom@mehr.sharif.ir
1
Department of Mathematical Sciences, Sharif University of Technology, Tehran, Iran.
It is shown that the knowledge of a surjective morphism $X\to Y$ of complex curves can be effectively used to make explicit calculations. The method is demonstrated by the calculation of $j(n\tau)$ (for some small $n$) in terms of $j(\tau)$ for the elliptic curve with period lattice $(1,\tau)$, the period matrix for the Jacobian of a family of genus-$2$ curves complementing the classic calculations of Bolza and explicit general formulae for branched covers of an elliptic curve with exactly one ramification point.
http://bims.iranjournals.ir/article_1079_545c2bcc6cfdf11ec7739e314d3a881f.pdf
Algebraic curves
branched covers
elliptic curves
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
2017
2025
1080
Upper bounds for noetherian dimension of all injective modules with Krull dimension
S.J. Hashemi Zadeh Dezfuli
jhashemi@scu.ac.ir
1
M. Zholanezhad
mohsenzhola@yahoo.com
2
Department of Mathematics, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Department of Mathematics, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
In this paper we give an upper bound for Noetherian dimension of all injective modules with Krull dimension on arbitrary rings. In particular, we also give an upper bound for Noetherian dimension of all Artinian modules on Noetherian duo rings.
http://bims.iranjournals.ir/article_1080_f46e865bcb496ef8b2f73ce9509d0735.pdf
Noetherian dimension
Artinian modules
injective modules
comonoform right ideals
duo rings
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
2027
2050
1081
Locally finite basic classical simple Lie superalgebras
M. Yousofzadeh
yousofzadeh2001@yahoo.com
1
Department of Mathematics, University of Isfahan, Isfahan, Iran, P.O. Box 81745-163
In this work, we study direct limits of finite dimensional basic classical simple Lie superalgebras and obtain the conjugacy classes of Cartan subalgebras under the group of automorphisms.
http://bims.iranjournals.ir/article_1081_09a5fb4afd52490e52e8c06dd7e434b5.pdf
Locally finite Lie superalgebra
finite dimensional basic classical simple Lie superalgebra
Cartan subalgebra
conjugacy classes
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
2051
2056
1082
On normalizers of maximal subfields of division algebras
M. Motiee
motiee@nit.ac.ir
1
Faculty of Basic Sciences, Babol Noshirvani University of Technology, Shariati Ave., Babol, Post Code 47148-71167, Iran.
Here, we investigate a conjecture posed by Amiri and Ariannejad claiming that if every maximal subfield of a division ring $D$ has trivial normalizer, then $D$ is commutative. Using Amitsur classification of finite subgroups of division rings, it is essentially shown that if $D$ is finite dimensional over its center then it contains a maximal subfield with non-trivial normalizer if and only if $D^*$ contains a non-abelian soluble subgroup. This result generalizes a theorem of Mahdavi-Hezavehi and Tignol about cyclicity of division algebras of prime index.
http://bims.iranjournals.ir/article_1082_46171c8ef1baa76a91c6ee91c20ac491.pdf
Division algebras
cyclic algebras
soluble groups
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-01
43
6
2057
2066
1083
Singular values of convex functions of matrices
Z. Ulukök
zbydmatrix@gmail.com
1
Vadi Park Sit., Gulvatan Sok., Yazir, Selçuklu, 42250, Konya, Turkey.
Let $A_{i},B_{i},X_{i},i=1,\dots,m,$ be $n$-by-$n$ matrices such that $\sum_{i=1}^{m}\left\vert A_{i}\right\vert ^{2}$ and $\sum_{i=1}^{m}\left\vert B_{i}\right\vert ^{2}$ are nonzero matrices and each $X_{i}$ is positive semidefinite. It is shown that if $f$ is a nonnegative increasing convex function on $\left[ 0,\infty \right) $ satisfying $f\left( 0\right) =0 $, then $$2s_{j}\left( f\left( \frac{\left\vert \sum_{i=1}^{m}A_{i}^{\ast }X_{i}B_{i}\right\vert }{\sqrt{\left\Vert \sum_{i=1}^{m}\left\vert A_{i}\right\vert ^{2}\right\Vert \left\Vert \sum_{i=1}^{m}\left\vert B_{i}\right\vert ^{2}\right\Vert }}\right) \right) \leq s_{j}\left( \oplus _{i=1}^{m}f\left( 2X_{i}\right) \right)$$ for $j=1,\ldots,n$. Applications of our results are given.
http://bims.iranjournals.ir/article_1083_327a7a884377fbd11d819f33653250c0.pdf
Singular value
arithmetic-geometric mean
direct sum
positive semidefinite matrix
convex function
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
2067
2084
1084
A new hybrid conjugate gradient algorithm for unconstrained optimization
X. Han
hanmath@163.com
1
J. Zhang
zhangjr@swu.edu.cn
2
J. Chen
j.w.chen713@163.com
3
School of Mathematics and Statistics, Southwest University, Chongqing 400715, P.R. China.
School of Mathematics and Statistics, Southwest University, Chongqing 400715, P.R. China.
School of Mathematics and Statistics, Southwest University, Chongqing 400715, P.R. China.
In this paper, a new hybrid conjugate gradient algorithm is proposed for solving unconstrained optimization problems. This new method can generate sufficient descent directions unrelated to any line search. Moreover, the global convergence of the proposed method is proved under the Wolfe line search. Numerical experiments are also presented to show the efficiency of the proposed algorithm, especially for solving highly dimensional problems.
http://bims.iranjournals.ir/article_1084_109497f29bf88715b9cadc58859c6be0.pdf
Unconstrained optimization problem
hybrid conjugate gradient algorithm
sufficient descent directions
global convergence
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
2085
2097
1085
Some results on pre-monotone operators
M.H. Alizadeh
alizadehmohammadh@gmail.com
1
M. Roohi
m.roohi@gu.ac.ir
2
Department of Mathematics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran.
Department of Mathematics, Faculty of Sciences, Golestan University, P.O. Box 155, Gorgan, Iran.
In this paper, some properties of pre-monotone operators are proved. It is shown that in a reflexive Banach space, a full domain multivalued $\sigma$-monotone operator with sequentially norm$\times$weak$^*$ closed graph is norm$\times$weak$^*$ upper semicontinuous. The notion of $\sigma$-convexity is introduced and the relations between the $\sigma$-monotonicity and $\sigma$-convexity is investigated. Moreover, some results on the sum and difference of two $\sigma$-monotone operators is considered.
http://bims.iranjournals.ir/article_1085_cc4d2b57b686d6c39e4e826525d95114.pdf
Generalized monotone operators
upper semicontinuous
convex function
eng
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
2017-11-30
43
6
2099
2110
1086
Non-homogeneous continuous and discrete gradient systems: the quasi-convex case
H. Khatibzadeh
hkhatibzadeh@znu.ac.ir
1
V. Mohebbi
mohebbi@znu.ac.ir
2
Department of Mathematics, University of Zanjan, P. O. Box 45195-313, Zanjan, Iran.
Department of Mathematics, University of Zanjan, P. O. Box 45195-313, Zanjan, Iran.
In this paper, first we study the weak and strong convergence of solutions to the following first order nonhomogeneous gradient system $$\begin{cases}-x'(t)=\nabla\phi(x(t))+f(t),\ \ \ \ \text{a.e.\ \ on}\ (0,\infty)\\x(0)=x_0\in H\end{cases}$$ to a critical point of $\phi$, where $\phi$ is a $C^1$ quasi-convex function on a real Hilbert space $H$ with ${\rm Argmin}\phi\neq\varnothing$ and $f\in L^1(0,+\infty;H)$. These results extend the results in the literature to non-homogeneous case. Then the discrete version of the above system by backward Euler discretization has been studied. Beside of the proof of the existence of the sequence given by the discrete system, someresults on the weak and strong convergence to the critical point of $\phi$ are also proved. These results when $\phi$ is pseudo-convex (therefore the critical points are the same minimum points) may be applied in optimization for approximation of a minimum point of $\phi$.
http://bims.iranjournals.ir/article_1086_c9f5c603ae165a46745899906352a83b.pdf
Gradient system
quasi-convex
backward Euler discretization
weak convergence
strong convergence