2019-03-26T23:58:58Z
http://bims.iranjournals.ir/?_action=export&rf=summon&issue=96
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Bulletin of the Iranian Mathematical Society
2017
11
01
http://bims.iranjournals.ir/article_1254_ceede3403839cdf5982d1f99755dc888.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Caratheodory dimension for observers
M.R.
Molaei
Y.
Sayyari
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.
Caratheodory structure
observer
news spread
Hausdorff dimension
2017
11
30
1559
1570
http://bims.iranjournals.ir/article_1034_60a101abff7a9ba09724f8efa7ac7b21.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
On three-dimensional $N(k)$-paracontact metric manifolds and Ricci solitons
U.C.
De
S.
Deshmukh
K.
Mandal
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.
Ricci semisymmetric
cyclic parallel Ricci tensor
$eta$-parallel Ricci tensor
Ricci soliton
Einstein manifold
2017
11
30
1571
1583
http://bims.iranjournals.ir/article_1040_a446023e2cc7956949c8c04a16793c63.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Decay estimates of solutions to the IBq equation
Y.
Zhang
P.
Li
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 $L^q(1leq qleq 2)$ 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.
IBq equation
global existence
decay estimates
asymptotic profile
2017
11
30
1585
1600
http://bims.iranjournals.ir/article_1038_738b44c2e71a0ee521ae3bc6352b4008.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Functional identities of degree 2 in CSL algebras
D.
Han
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 $F_1, F_2, G_1, G_2colon {rm Alg}mathscr{L}longrightarrow mathscr{M}$ satisfying functional identity $F_1(X)Y+F_2(Y)X+XG_2(Y)+YG_1(X)=0$ for all $X, Yin {rm Alg}mathscr{L}$. As an application generalized inner biderivations and commuting additive mappings are determined.
Functional identity
CSL algebra
generalized inner biderivation
commuting mapping
2017
11
30
1601
1619
http://bims.iranjournals.ir/article_1035_743a4e08ff10b2e3cd9fa16b23cc1eae.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
The length of Artinian modules with countable Noetherian dimension
M.
Davoudian
O.
Ghayour
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 $omega ^{alpha }+2leq it{l}(M)leq omega ^{alpha +1}$, 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 $M$.
Artinian module
Noetherian dimension
atomic module
the length of an R-module
2017
11
30
1621
1628
http://bims.iranjournals.ir/article_1042_3a9a8677dfa67377a62a97351e3a6e04.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
On derivations and biderivations of trivial extensions and triangular matrix rings
N.M.
Ghosseiri
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.
Trivial extension
triangular matrix ring
derivation
biderivation
2017
11
30
1629
1644
http://bims.iranjournals.ir/article_1044_21e6b15378858865b24096a56c02831e.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Two-geodesic transitive graphs of prime power order
W.
Jin
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.
2-geodesic transitive graph
2-arc transitive graph
automorphism group
2017
11
30
1645
1655
http://bims.iranjournals.ir/article_1045_dfcf1e1367b8d9455343433f1e659a9c.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Stability of F-biharmonic maps
S.M.
Kazemi Torbaghan
M.M.
Rezaii
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.
Biharmonic maps
F-biharmonic maps
conformal maps
stability
2017
11
30
1657
1669
http://bims.iranjournals.ir/article_1049_6c770288ef08175535eb53634c6ca3a0.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Gorenstein hereditary rings with respect to a semidualizing module
G.
Zhao
B.
Zhang
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.
Semidualizing module
$G_C$-projective module
$G_C$-flat module
$G_C$-(semi)hereditary ring
coherent ring
2017
11
30
1671
1677
http://bims.iranjournals.ir/article_1052_a5c3f63a6c7c776ea5aa5f168bb1c109.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Duality for vector equilibrium problems with constraints
N.L.H.
Anh
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.
Equilibrium problem
duality
optimality conditions
quasi-relative efficient solution
generalized subconvexlikeness
2017
11
30
1679
1694
http://bims.iranjournals.ir/article_1053_eba0fe1a292ed8178692f970c5e4725a.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
An upper bound for the regularity of powers of edge ideals
M.
Moghimian
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 $sgeq 1$, $${rm reg}( R/ I(G)^{s})leq (2s-1) |E(G)|^{s-1} {rm match}(G).$$
Edge ideal
Castelnuovo-Mumford regularity
matching number
2017
11
30
1695
1698
http://bims.iranjournals.ir/article_1054_da3531e9ece50748643698a60817cad6.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Properties of matrices with numerical ranges in a sector
D.
Zhang
L.
Hou
L.
Ma
Let $(A)$ be a complex $(ntimes n)$ 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 $(S_{alpha})$.<br />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.
Numerical ranges
sector
positive definite
Toeplitz decomposition
2017
11
30
1699
1707
http://bims.iranjournals.ir/article_1056_b52b59d9cddfb9e022bc31ed6322b513.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
On nuclei of sup-$Sigma$-algebras
X.
Zhang
Y.
Zhou
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.
Sup-$Sigma$-algebra
nucleus
congruence
quotient
2017
11
30
1709
1721
http://bims.iranjournals.ir/article_1057_99be559b2c84987c08fb22e247fad759.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
High-accuracy alternating segment explicit-implicit method for the fourth-order heat equation
G.
Guo
S.
Lü
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 the<br />present method that are in preference to the prior methods.
Fourth-order heat equation
alternating segment explicit-implicit method
high accuracy
parallel computation
unconditional stability
2017
11
30
1723
1737
http://bims.iranjournals.ir/article_1059_993ed41f72e1186dd00628a34c963615.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Applications of convolution and subordination to certain $p$-valent functions
S.
Hussain
J.
Sokół
U.
Farooq
M.
Darus
T.
Mahmood
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.
Multivalent function
convolution
Subordination
linear operator
2017
11
30
1739
1749
http://bims.iranjournals.ir/article_1060_2c675a7b7dd48d7b233b76c37b11a172.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Hölder continuity of solution maps to a parametric weak vector equilibrium problem
P.
Preechasilp
R.
wangkeeree
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.
Vector equilibrium problem
solution mapping
Hölder continuity
linear scalarization
2017
11
30
1751
1767
http://bims.iranjournals.ir/article_1065_2e8c10b5f887027ce679d1615238281e.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Hyperbolic surfaces of $L_1$-2-type
P.
Lucas
H.F.
Ramírez-Ospina
In this paper, we show that an $L_1$-2-type surface in the three-dimensional hyperbolic space $H^3subset R^4_1$ 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.
Hyperbolic surface
Cheng-Yau operator
$L_1$-finite-type surface
$L_1$-biharmonic surface
Newton transformation
2017
11
30
1769
1779
http://bims.iranjournals.ir/article_1062_5af9f5b2ebe4719b4560a0e48f304949.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
The second dual of strongly zero-product preserving maps
A.R.
Khoddami
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.
Strongly zero-product preserving map
strongly Jordan zero-product preserving map
strongly Lie zero-product preserving map
Arens regular
2017
11
30
1781
1790
http://bims.iranjournals.ir/article_1063_7b8628e66b977698b444316e36a92e54.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Classification of solvable groups with a given property
M.
Rezaei
Z.
Foruzanfar
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.
Frobenius group
Conjugacy classes
graph
order
2017
11
30
1791
1800
http://bims.iranjournals.ir/article_1064_5e25c91a6bdc31bbd41bfb454b5334ef.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
The graph of equivalence classes and Isoclinism of groups
R.
Rezaei
M.
Varmazyar
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 $V(Gamma(G))=Gsetminus Z(G)$ by taking $xsim y$ if and only if $N(x)=N(y)$, where $ N(x)={uin 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 ${[x] | x in Gsetminus Z(G)}$ 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.
Non-commuting graph
graph of equivalence classes
Isoclinism
2017
11
30
1801
1810
http://bims.iranjournals.ir/article_1061_2b7cba5aa6cdb3872025474bf8edf9fb.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Defining relations of a group $Gamma= G^{3,4}(2,Z)$ and its action on real quadratic field
M.
Ashiq
T.
Imran
M. A.
Zaighum
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 $r:zrightarrow frac{z-1}{z}$ and $s:zrightarrow frac{-1}{2(z+1)}$ 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.
Coset diagrams
modular group
linear-fractional transformations
real quadratic field
ambiguous numbers
2017
11
30
1811
1820
http://bims.iranjournals.ir/article_1066_6cbc8ab9f3f6e93ee2c811ce21ce6a68.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Entropy of a semigroup of maps from a set-valued view
B.
Hou
X.
Wang
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.
Topological entropy
semigroups
entropy-like invariants
Hausdorff metric
1999
11
30
1821
1835
http://bims.iranjournals.ir/article_1067_479aa58a4bb53422d87b5956ff62afe4.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Initial coefficients of starlike functions with real coefficients
S.
Kumar
V.
Ravichandran
S.
Verma
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
Coefficient estimates
starlike functions
close to convex functions
functions with positive real part
real coefficient
2017
11
30
1837
1854
http://bims.iranjournals.ir/article_1068_2d1a93d22ef0d7481f165dcb3825c786.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Classifying pentavalnet symmetric graphs of order $24p$
B.
Ling
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.
Symmetric graph
normal quotient
automorphism group
2017
11
30
1855
1866
http://bims.iranjournals.ir/article_1069_e6c795ff2cc2616cd81138a8139b0332.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
A weak approximation for the Extrema's distributions of Levy processes
A.T.
Payandeh Najafabadi
D.Z.
Kucerovsky
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 $1<pleq2$), 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.
Levy processes
positive-definite function
extrema's distributions
the Fourier transform
the Hilbert transform
2017
11
30
1867
1888
http://bims.iranjournals.ir/article_1244_7733deed4511081e9bceedc681ecc11b.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Existence of positive solutions for a second-order p-Laplacian impulsive boundary value problem on time scales
F.
Tokmak Fen
I.Y.
Karaca
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.
Impulsive boundary value problems
p-Laplacian
positive solutions
fixed point theorem
Time scales
2017
11
30
1889
1903
http://bims.iranjournals.ir/article_1070_da5504c917fa9b3f5a2cd16c41f2ca5a.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
When is the ring of real measurable functions a hereditary ring?
H.
Hejazipour
A. R.
Naghipour
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.
Measurable functions
hereditary rings
projective prime ideals
2017
11
30
1905
1912
http://bims.iranjournals.ir/article_1073_1eb98851b6536cbd289da1c626d55f8d.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Subdirectly irreducible acts over some semigroups
Gh.
Moghaddasi
M.
Mahmoudi
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.
Subdirectly irreducible
chain of semigroups
2017
11
30
1913
1924
http://bims.iranjournals.ir/article_1074_23345385ea8c6ec1307ceb3d81b2ed2b.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
The lower bound for the number of 1-factors in generalized Petersen graphs
H.
Ren
C.
Yang
J.
Wang
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).
Generalized Petersen graphs
matching
1-factors
Fibonacci number
2017
11
30
1925
1937
http://bims.iranjournals.ir/article_1075_cf616b56426d01c35cd3041b4df264ed.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Composition of resolvents and quasi-nonexpansive multivalued mappings in Hadamared spaces
G.
Zamani Eskandani
S.
Azarmi
M.
Eslamian
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.
Proximal point algorithm
$CAT(0)$ spaces
Nonexpansive multivalued mappings
2017
11
30
1939
1955
http://bims.iranjournals.ir/article_1076_669539101764946143d80ea1280ca7a4.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
A hybrid mean value involving a new Gauss sums and Dedekind sums
X.X.
Li
W.P.
Zhang
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.
A new Gauss sums
Dedekind sums
hybrid mean value
identity
analytic method
2017
11
30
1957
1968
http://bims.iranjournals.ir/article_1077_2158a37858112c93483a006a0f583088.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Semi-Rothberger and related spaces
A.
Sabah
M.
Khan
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.
Semi-open set, (star) semi-compact space
semi-Lindelöf space
s-Rothberger space
star s-Rothberger space
2017
11
30
1969
1987
http://bims.iranjournals.ir/article_1078_9fad6d520d7acfc75e636817ab29dff9.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
A descent method for explicit computations on curves
K.
Filom
It is shown that the knowledge of a surjective morphism $Xto Y$ of complex curves can be effectively used to make explicit calculations. The method is demonstrated by the calculation of $j(ntau)$ (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.
Algebraic curves
branched covers
elliptic curves
2017
11
30
1989
2016
http://bims.iranjournals.ir/article_1079_545c2bcc6cfdf11ec7739e314d3a881f.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Upper bounds for noetherian dimension of all injective modules with Krull dimension
S.J.
Hashemi Zadeh Dezfuli
M.
Zholanezhad
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.
Noetherian dimension
Artinian modules
injective modules
comonoform right ideals
duo rings
2017
11
30
2017
2025
http://bims.iranjournals.ir/article_1080_f46e865bcb496ef8b2f73ce9509d0735.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Locally finite basic classical simple Lie superalgebras
M.
Yousofzadeh
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.
Locally finite Lie superalgebra
finite dimensional basic classical simple Lie superalgebra
Cartan subalgebra
conjugacy classes
2017
11
30
2027
2050
http://bims.iranjournals.ir/article_1081_09a5fb4afd52490e52e8c06dd7e434b5.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
On normalizers of maximal subfields of division algebras
M.
Motiee
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.
Division algebras
cyclic algebras
soluble groups
2017
11
30
2051
2056
http://bims.iranjournals.ir/article_1082_46171c8ef1baa76a91c6ee91c20ac491.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Singular values of convex functions of matrices
Z.
Ulukök
Let $A_{i},B_{i},X_{i},i=1,dots,m,$ be $n$-by-$n$ matrices such that $sum_{i=1}^{m}leftvert A_{i}rightvert ^{2}$ and $sum_{i=1}^{m}leftvert B_{i}rightvert ^{2}$ 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 $fleft( 0right) =0 $, then <br /> $$2s_{j}left( fleft( frac{leftvert sum_{i=1}^{m}A_{i}^{ast }X_{i}B_{i}rightvert }{sqrt{leftVert sum_{i=1}^{m}leftvert<br /> A_{i}rightvert ^{2}rightVert leftVert sum_{i=1}^{m}leftvert<br /> B_{i}rightvert ^{2}rightVert }}right) right) leq s_{j}left( oplus<br /> _{i=1}^{m}fleft( 2X_{i}right) right)$$<br /> for $j=1,ldots,n$. Applications of our results are given.
Singular value
arithmetic-geometric mean
direct sum
positive semidefinite matrix
convex function
2017
11
01
2057
2066
http://bims.iranjournals.ir/article_1083_327a7a884377fbd11d819f33653250c0.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
A new hybrid conjugate gradient algorithm for unconstrained optimization
X.
Han
J.
Zhang
J.
Chen
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.
Unconstrained optimization problem
hybrid conjugate gradient algorithm
sufficient descent directions
global convergence
2017
11
30
2067
2084
http://bims.iranjournals.ir/article_1084_109497f29bf88715b9cadc58859c6be0.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Some results on pre-monotone operators
M.H.
Alizadeh
M.
Roohi
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.
Generalized monotone operators
upper semicontinuous
convex function
2017
11
30
2085
2097
http://bims.iranjournals.ir/article_1085_cc4d2b57b686d6c39e4e826525d95114.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
6
Non-homogeneous continuous and discrete gradient systems: the quasi-convex case
H.
Khatibzadeh
V.
Mohebbi
In this paper, first we study the weak and strong convergence of solutions to the following first order nonhomogeneous gradient system $$begin{cases}-x'(t)=nablaphi(x(t))+f(t), text{a.e. on} (0,infty)\x(0)=x_0in Hend{cases}$$ to a critical point of $phi$, where $phi$ is a $C^1$ quasi-convex function on a real Hilbert space $H$ with ${rm Argmin}phineqvarnothing$ and $fin L^1(0,+infty;H)$. 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 $phi$.
Gradient system
quasi-convex
backward Euler discretization
weak convergence
strong convergence
2017
11
30
2099
2110
http://bims.iranjournals.ir/article_1086_c9f5c603ae165a46745899906352a83b.pdf