2018-07-22T09:01:37Z
http://bims.iranjournals.ir/?_action=export&rf=summon&issue=97
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Bulletin of the Iranian Mathematical Society
2017
12
01
http://bims.iranjournals.ir/article_1268_f3e714e90425ad0c50a7e73722850b9c.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Existence of ground state solutions for a class of nonlinear elliptic equations with fast increasing weight
L.
Li
C.-L.
Tang
This paper is devoted to get a ground state solution for a class of nonlinear elliptic equations with fast increasing weight. We apply the variational methods to prove the existence of ground state solution.
Self-similar solution
variational methods
ground state solution
2017
12
01
2111
2124
http://bims.iranjournals.ir/article_975_ecb7585b5b420bce9f6305db16fb169e.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
The ranks of the classes of $A_{10}$
A.B.M.
Basheer
Let $G $ be a finite group and $X$ be a conjugacy class of $G.$ The rank of $X$ in $G,$ denoted by $rank(G{:}X),$ is defined to be the minimal number of elements of $X$ generating $G.$ In this paper we establish the ranks of all the conjugacy classes of elements for simple alternating group $A_{10}$ using the structure constants method and other results established in [A.B.M. Basheer and J. Moori, On the ranks of the alternating group $A_{n}$, Bull. Malays. Math. Sci. Soc..
Conjugacy classes
rank
generation
structure constant
alternating group
2017
12
01
2125
2135
http://bims.iranjournals.ir/article_1266_a66ae7592033b2fce476a115f015c8c9.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
$n$-Array Jacobson graphs
H.
Ghayour
A.
Erfanian
A.
Azimi
M.
Farrokhi D. G.
We generalize the notion of Jacobson graphs into $n$-array columns called $n$-array Jacobson graphs and determine their connectivities and diameters. Also, we will study forbidden structures of these graphs and determine when an $n$-array Jacobson graph is planar, outer planar, projective, perfect or domination perfect.
Jacobson graph
connectivity
planar graph
outer planar graph
perfect graph
2017
12
30
2137
2152
http://bims.iranjournals.ir/article_1072_3d36aa6ead210c64097db60ede73c5ad.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Inequalities for the polar derivative of a polynomial with $S$-fold zeros at the origin
E.
Khojastehnezhad
M.
Bidkham
Let $p(z)$ be a polynomial of degree $n$ and for a complex number $alpha$, let $D_{alpha}p(z)=np(z)+(alpha-z)p'(z)$ denote the polar derivative of the polynomial p(z) with respect to $alpha$. Dewan et al proved that if $p(z)$ has all its zeros in $|z| leq k, (kleq 1),$ with $s$-fold zeros at the origin then for every $alphainmathbb{C}$ with $|alpha|geq k$, begin{align*} max_{|z|=1}|D_{alpha}p(z)|geq frac{(n+sk)(|alpha|-k)}{1+k}max_{|z|=1}|p(z)|. end{align*} In this paper, we obtain a refinement of above inequality. Also as an application of our result, we extend some inequalities for polar derivative of a polynomial of degree $n$ which does not vanish in $|z|< k$, where $kgeq 1$, except $s$-fold zeros at the origin.
Polynomial
inequality
maximum modulus
polar derivative
restricted zeros
2017
12
30
2153
2167
http://bims.iranjournals.ir/article_1087_e2275691daabd2435b3f62bfe31eedef.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
On $Phi$-$tau$-quasinormal subgroups of finite groups
Y.
Mao
X.
Ma
X.
Tang
J.
Huang
Let $tau$ be a subgroup functor and $H$ a $p$-subgroup of a finite group $G$. Let $bar{G}=G/H_{G}$ and $bar{H}=H/H_{G}$. We say that $H$ is $Phi$-$tau$-quasinormal in $G$ if for some $S$-quasinormal subgroup $bar{T}$ of $bar{G}$ and some $tau$-subgroup $bar{S}$ of $bar{G}$ contained in $bar{H}$, $bar{H}bar{T}$ is $S$-quasinormal in $bar{G}$ and $bar{H}capbar{T}leq bar{S}Phi(bar{H})$. In this paper, we study the structure of a group $G$ under the condition that some primary subgroups of $G$ are $Phi$-$tau$-quasinormal in $G$. Some new characterizations about $p$-nilpotency and solubility of finite groups are obtained.
$S$-quasinormal subgroups
$p$-nilpotent subgroups, subgroup functor
soluble group
2017
12
30
2169
2182
http://bims.iranjournals.ir/article_1088_42c83e5c0a23d661fa95aaa1ad32dcfa.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Linear codes with complementary duals related to the complement of the Higman-Sims graph
B.G.
Rodrigues
In this paper we study codes $C_p(overline{{rm HiS}})$ where $p =3,7, 11$ defined by the 3- 7- and 11-modular representations of the simple sporadic group ${rm HS}$ of Higman and Sims of degree 100. With exception of $p=11$ the codes are those defined by the row span of the adjacency matrix of the complement of the Higman-Sims graph over $GF(3)$ and $GF(7).$ We show that these codes have a similar decoding performance to that of their binary counterparts obtained from the Higman-Sims graph. In particular, we show that these are linear codes with complementary duals, and thus meet the asymptotic Gilbert-Varshamov bound. Furthermore, using the codewords of weight 30 in $C_p(overline{{rm HiS}})$ we determine a subcode of codimension 1, and thus show that the permutation module of dimension 100 over the fields of 3, 7 and 11-elements, respectively is the direct sum of three absolutely irreducible modules of dimensions 1, 22 and 77. The latter being also the subdegrees of the orbit decomposition of the rank-3 representation.
Strongly regular graph
Higman-Sims graph
linear code
automorphism group
2017
12
30
2183
2204
http://bims.iranjournals.ir/article_1253_82f0207ea7f159c1fbcdbf2bda09cf56.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Zero elements and $z$-ideals in modified pointfree topology
A.A.
Estaji
A.
Karimi Feizabad
M.
Zarghani
In this paper, we define and study the notion of zero elements in topoframes; a topoframe is a pair $(L, tau)$, abbreviated $L_{ tau}$, consisting of a frame $L$ and a subframe $ tau $ all of whose elements are complemented elements in $L$. We show that the $f$-ring $ mathcal{R}(L_tau)$, the set of $tau$-real continuous functions on $L$, is uniformly complete. Also, the set of all zero elements in a topoframe is closed under the formation of countable meets and finite joins. Also, we introduce the notion of $z$-filters and $z$-ideals in modified pointfree topology and make ready some results about them.
Topoframe
zero element
$z$-filter
$z$-ideal
prime ideal
2017
12
30
2205
2226
http://bims.iranjournals.ir/article_1090_17ec79f62279ac897d5fe7ebab2a0ff0.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Modules whose direct summands are FI-extending
O.
Tasdemir
F.
Karabacak
A module $M$ is called FI-extending if every fully invariant submodule of $M$ is essential in a direct summand of $M$. It is not known whether a direct summand of an FI-extending module is also FI-extending. In this study, it is given some answers to the question that under what conditions a direct summand of an FI-extending module is an FI-extending module?
Extending module
direct summand
left exact preradical
2017
12
30
2227
2231
http://bims.iranjournals.ir/article_1091_7994dad656774b761f268faf15e8955e.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Duality for the class of a multiobjective problem with support functions under $K$-$G_f$-invexity assumptions
I.P.
Debnath
S.K.
Gupta
In this article, we formulate two dual models Wolfe and Mond-Weir related to symmetric nondifferentiable multiobjective programming problems. Furthermore, weak, strong and converse duality results are established under $K$-$G_f$-invexity assumptions. Nontrivial examples have also been depicted to illustrate the theorems obtained in the paper. Results established in this paper unify and extend some previously known results appeared in the literature
Multiobjective programming
$K$-$G_f$-invexity
support function
efficient solutions
duality
2017
12
30
2233
2258
http://bims.iranjournals.ir/article_1096_85013b0bfd27489b5e154ca9baeafd3d.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
The $w$-FF property in trivial extensions
G.W.
Chang
H.
Kim
Let $D$ be an integral domain with quotient field $K$, $E$ be a $K$-vector space, $R = D propto E$ be the trivial extension of $D$ by $E$, and $w$ be the so-called $w$-operation. In this paper, we show that $R$ is a $w$-FF ring if and only if $D$ is a $w$-FF domain; and in this case, each $w$-flat $w$-ideal of $R$ is $w$-invertible.
$w$-flat module
$w$-FF ring
trivial extension
2017
12
30
2259
2267
http://bims.iranjournals.ir/article_1095_d06f8dc061cfad739bf3eb28268245a3.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Localization at prime ideals in bounded rings
E.
Akalan
B.
Saraç
In this paper we investigate the sufficiency criteria which guarantee the classical localization of a bounded ring at its prime ideals.
Localization
projective ideal
eventually idempotent ideal
bounded rings
2017
12
30
2269
2274
http://bims.iranjournals.ir/article_1098_c5be1040f7c106f382e2d16e3c9dd327.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
$L^p$ boundedness of the Bergman projection on some generalized Hartogs triangles
T.
Beberok
In this paper we investigate a two classes of domains in $mathbb{C}^n$ generalizing the Hartogs triangle. We prove optimal estimates for the mapping properties of the Bergman projection on these domains.
Hartogs triangle
Bergman projection
Bergman kernel
2017
12
30
2275
2280
http://bims.iranjournals.ir/article_1102_c8f9b4afbe18af80c73696409cfed7fa.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
On the fixed number of graphs
I.
Javaid
M.
Murtaza
M.
Asif
F.
Iftikhar
A set of vertices $S$ of a graph $G$ is called a fixing set of $G$, if only the trivial automorphism of $G$ fixes every vertex in $S$. The fixing number of a graph is the smallest cardinality of a fixing set. The fixed number of a graph $G$ is the minimum $k$, such that every $k$-set of vertices of $G$ is a fixing set of $G$. A graph $G$ is called a $k$-fixed graph, if its fixing number and fixed number are both $k$. In this paper, we study the fixed number of a graph and give a construction of a graph of higher fixed number from a graph of lower fixed number. We find the bound on $k$ in terms of the diameter $d$ of a distance-transitive $k$-fixed graph.
Fixing set
stabilizer
fixing number
fixed number
2017
12
30
2281
2292
http://bims.iranjournals.ir/article_1103_6cf076c09b16e5ab488956cbcfb99dc5.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Filter theory in MTL-algebras based on Uni-soft property
G.
Muhiuddin
A.M.
Al-roqi
S.
Aldhafeeri
The notion of (Boolean) uni-soft filters in MTL-algebras is introduced, and several properties of them are investigated. Characterizations of (Boolean) uni-soft filters are discussed, and some (necessary and sufficient) conditions for a uni-soft filter to be Boolean are provided. The condensational property for a Boolean uni-soft filter is established.
MTL-algebras
(Boolean) filter
(Boolean) uni-soft filter
2017
12
30
2293
2306
http://bims.iranjournals.ir/article_1104_0122114dd4208fd2c85fb7f526d0e470.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Determination of a jump by Fourier and Fourier-Chebyshev series
M.
Avdispahic
Z.
Sabanac
By observing the equivalence of assertions on determining the jump of a function by its differentiated or integrated Fourier series, we generalize a previous result of Kvernadze, Hagstrom and Shapiro to the whole class of functions of harmonic bounded variation. This is achieved without the finiteness assumption on the number of discontinuities. Two results on determination of jump discontinuities by means of the tails of integrated Fourier-Chebyshev series are also derived.
Fourier series
generalized bounded variation
jump discontinuities
2017
12
30
2307
2321
http://bims.iranjournals.ir/article_1107_f7490af1557c52224e87a714057dc4e6.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Improved logarithmic-geometric mean inequality and its application
L.
Zou
In this short note, we present a refinement of the logarithmic-geometric mean inequality. As an application of our result, we obtain an operator inequality associated with geometric and logarithmic means.
Taylor's Theorem
logarithmic mean
geometric mean
operator inequality
2017
12
30
2323
2326
http://bims.iranjournals.ir/article_1110_a2473c8ce3620a45bb9b80377280bcee.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
On rational groups with Sylow 2-subgroups of nilpotency class at most 2
S.
Jafari
H.
Sharifi
A finite group $G$ is called rational if all its irreducible complex characters are rational valued. In this paper we discuss about rational groups with Sylow 2-subgroups of nilpotency class at most 2 by imposing the solvability and nonsolvability assumption on $G$ and also via nilpotency and nonnilpotency assumption of $G$.
Rational group
nilpotency class
Markel group
2017
12
30
2327
2337
http://bims.iranjournals.ir/article_1113_58118f7c20f56a8f682e23695d8efc9e.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Historic set carries full hausdorff dimension
G.-Z.
Ma
We prove that the historic set for ratio of Birkhoff average is either empty or full of Hausdorff dimension in a class of one dimensional non-uniformly hyperbolic dynamical systems.
Historic set
Moran set
non-uniformly hyperbolic
2017
12
30
2339
2347
http://bims.iranjournals.ir/article_1115_1c9ffd5a7475a95dd5b010f5426739bf.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
On subgroups of topologized fundamental groups and generalized coverings
M.
Abdullahi Rashid
B.
Mashayekhy
H.
Torabi
S. Z.
Pashaei
In this paper, we are interested in studying subgroups of topologized fundamental groups and their influences on generalized covering maps.
More precisely, we find some relationships between generalized covering subgroups and the other famous subgroups of the fundamental group equipped with the compact-open topology and the whisker topology. Moreover, we present some conditions under which generalized coverings, semicoverings and coverings are equal.
Generalized covering
quasitopological fundamental group
whisker topology
semilocally small generated
homotopically Hausdorff
2017
12
30
2349
2370
http://bims.iranjournals.ir/article_1116_8152556e767eda520078c714dca68e25.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Hölder continuity of a parametric variational inequality
X.F.
Hu
X.B.
Li
In this paper, we study the Hölder continuity of solution mapping to a parametric variational inequality. At first, recalling a real-valued gap function of the problem, we discuss the Lipschitz continuity of the gap function. Then under the strong monotonicity, we establish the Hölder continuity of the single-valued solution mapping for the problem. Finally, we apply these results to a traffic network equilibrium problem.
Hölder continuity
gap function
parametric variational inequality
traffic network equilibrium problem
2017
12
30
2371
2381
http://bims.iranjournals.ir/article_1120_3a0fbd1dd9a32d7853f443d5e6ca9ee8.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Self-similar solutions of the Riemann problem for two-dimensional systems of conservation laws
S.
Ayad
In this paper, a new approach is applied to study the self-similar solutions of 2×2 systems of nonlinear hyperbolic conservation laws. A notion of characteristic directions is introduced and then used to construct local and smooth solutions of the associated Riemann problem
Self-similar solutions
Riemann problem
Hyperbolic conservation laws
Smooth solutions
2017
12
30
2383
2392
http://bims.iranjournals.ir/article_1121_26684545248f1df176c79bb1a94bf1c4.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Existence and uniqueness of weak solutions for a class of nonlinear divergence type diffusion equations
P.
Chen
In this paper, we study the Neumann boundary value problem of a class of nonlinear divergence type diffusion equations. By a priori estimates, difference and variation techniques, we establish the existence and uniqueness of weak solutions of this problem.
Existence
uniqueness
weak solution
variation problem
$mathcal{N}$-function
2017
12
30
2393
2410
http://bims.iranjournals.ir/article_1123_7319df9a4111d5ef1d112580fe279f75.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Bounds for the dimension of the $c$-nilpotent multiplier of a pair of Lie algebras
H.
Arabyani
In this paper, we study the Neumann boundary value problem of a class of nonlinear divergence type diffusion equations. By a priori estimates, difference and variation techniques, we establish the existence and uniqueness of weak solutions of this problem.
Pair of Lie algebras
Schur multiplier
c-nilpotent multiplier
2017
12
30
2411
2418
http://bims.iranjournals.ir/article_1126_77d79494191993b54fb703b7b2bb6ffd.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Solving two-dimensional fractional integro-differential equations by Legendre wavelets
M.
Mojahedfar
A.
Tari Marzabad
In this paper, we introduce the two-dimensional Legendre wavelets (2D-LWs), and develop them for solving a class of two-dimensional integro-differential equations (2D-IDEs) of fractional order. We also investigate convergence of the method. Finally, we give some illustrative examples to demonstrate the validity and efficiency of the method.
Two-dimensional integro-differential equations
fractional operators
Legendre wavelets
operational matrix
2017
12
30
2419
2435
http://bims.iranjournals.ir/article_1127_13f6e0db0fd1a7124eeba0587cc7fb54.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Extensions of the Hestenes-Stiefel and Polak-Ribiere-Polyak conjugate gradient methods with sufficient descent property
S.
Babaie-Kafaki
R.
Ghanbari
Using search directions of a recent class of three--term conjugate gradient methods, modified versions of the Hestenes-Stiefel and Polak-Ribiere-Polyak methods are proposed which satisfy the sufficient descent condition. The methods are shown to be globally convergent when the line search fulfills the (strong) Wolfe conditions. Numerical experiments are done on a set of CUTEr unconstrained optimization test problems. They demonstrate efficiency of the proposed methods in the sense of the Dolan-More performance profile.
Unconstrained optimization
conjugate gradient method
sufficient descent property
line search
global convergence
2017
12
01
2437
2448
http://bims.iranjournals.ir/article_1128_0b073c64c95e8808e5bc16015697853c.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
On a Picone's identity for the $mathcal{A}_{p(x)}$-Laplacian and its applications
S.H.
Rasouli
We present a Picone's identity for the $mathcal{A}_{p(x)}$-Laplacian, which is an extension of the classic identity for the ordinary Laplace. Also, some applications of our results in Sobolev spaces with variable exponent are suggested.
Picone's identity
$mathcal{A}_{p(x)}$-Laplacian
Nonlinear elliptic problems
2017
12
30
2449
2455
http://bims.iranjournals.ir/article_1137_05c4064c2f06bc59855a9bd882a9da8d.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
On the Noetherian dimension of Artinian modules with homogeneous uniserial dimension
A.R.
Alehafttan
N.
Shirali
In this article, we first show that non-Noetherian Artinian uniserial modules over commutative rings, duo rings, finite $R$-algebras and right Noetherian rings are $1$-atomic exactly like $Bbb Z_{p^{infty}}$. Consequently, we show that if $R$ is a right duo (or, a right Noetherian) ring, then the Noetherian dimension of an Artinian module with homogeneous uniserial dimension is less than or equal to $1$. In particular, if $A$ is a quotient finite dimensional $R$-module with homogeneous uniserial dimension, where $R$ is a locally Noetherian (or, a Noetherian duo) ring, then $n$-dim $Aleq 1$. We also show that the Krull dimension of Noetherian modules is bounded by the uniserial dimension of these modules. Moreover, we introduce the concept of qu-uniserial modules and by using this concept, we observe that if $A$ is an Artinian $R$-module, such that any of its submodules is qu-uniserial, where $R$ is a right duo (or, a right Noetherian) ring, then $n$-dim $Aleq 1$.
Noetherian dimension
homogeneous uniserial dimension
atomic modules
2017
12
30
2457
2470
http://bims.iranjournals.ir/article_1146_2706ad754c4976e7ef148b92f0a82975.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Distinguishing number and distinguishing index of natural and fractional powers of graphs
S.
Alikhani
S.
Soltani
The distinguishing number (resp. index) $D(G)$ ($D'(G)$) of a graph $G$ is the least integer $d$
such that $G$ has an vertex labeling (resp. edge labeling) with $d$ labels that is preserved only by a trivial
automorphism. For any $n in mathbb{N}$, the $n$-subdivision of $G$ is a simple graph $G^{frac{1}{n}}$ which is constructed by replacing each edge of $G$ with a path of length $n$.
The $m^{th}$ power of $G$, is a graph with same set of vertices of $G$ and an edge between two vertices if and only if there is a path of length at most $m$ between them in $G$.
The fractional power of $G$, is the $m^{th}$ power of the $n$-subdivision of $G$, i.e., $(G^{frac{1}{n}})^m$ or $n$-subdivision of $m$-th power of $G$, i.e., $(G^m)^{frac{1}{n}}$. In this paper we study the distinguishing number and the distinguishing index of the natural and the fractional powers of $G$. We show that the natural powers more than one of a graph are distinguished by at most three edge labels. We also show that for a connected graph $G$ of order $n geqslant 3$ with maximum degree $Delta (G)$, and for $kgeqslant 2$, $D(G^{frac{1}{k}})leqslant lceil sqrt[k]{Delta (G)} rceil$. Finally we prove that for $mgeqslant 2$, the fractional power of $G$, i.e., $(G^{frac{1}{k}})^m$ and $(G^m)^{frac{1}{k}}$ are distinguished by at most three edge labels.
Distinguishing index
distinguishing number
fractional power
2017
12
01
2471
2482
http://bims.iranjournals.ir/article_1148_6e91ca9abade6c5324063dfe5d00fcce.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Characterization of $2times 2$ full diversity space-time codes and inequivalent full rank spaces
H.
Momenaee Kermani
M.
Ashenab
In wireless communication systems, space-time codes are applied to encode data when multiple antennas are used in the receiver and transmitter. The concept of diversity is very crucial in designing space-time codes. In this paper, using the equivalent definition of full diversity space-time codes, we first characterize all real and complex $2times 2$ rate one linear dispersion space-time block codes that are full diversity. This characterization is used to construct full diversity codes which are not derived from Alamouti scheme. Then, we apply our results to characterize all real subspaces of $M_{2}(mathbb{C})$ and $M_{2}(mathbb{R})$ whose nonzero elements are invertible. Finally, for any natural number $n>1$, we construct infinitely many inequivalent subspaces of $M_{n}(mathbb{C})$ whose nonzero elements are invertible.
Space-time coding
linear dispersion
full diversity
full rank
2017
12
30
2483
2493
http://bims.iranjournals.ir/article_1174_53974d9400ee9e1f4349ffd74f245181.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
A characterization of orthogonality preserving operators
E.
Ansari-piri
R.G.
Sanati
M.
Kardel
In this paper, we characterize the class of orthogonality preserving operators on an infinite-dimensional Hilbert space $H$ as scalar multiples of unitary operators between $H$ and some closed subspaces of $H$. We show that any circle (centered at the origin) is the spectrum of an orthogonality preserving operator. Also, we prove that every compact normal operator is a strongly orthogonality preserving operator.
Orthogonality preserving operators
adjoint of operators
isometry
unitary operators
2017
12
30
2495
2505
http://bims.iranjournals.ir/article_1181_ac6e9a52abbf950860c93074399ab8f1.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
State spaces of $K_0$ groups of some rings
J.
Ren
Let $R$ be a ring with the Jacobson radical $J(R)$ and let $picolon Rto R/J(R)$ be the canonical map. Then $pi$ induces an order preserving group homomorphism $K_0picolon K_0(R)to K_0(R/J(R))$ and an affine continuous map $S(K_0pi)$ between the state space $St(R/J(R))$ and the state space $St(R).$ In this paper, we consider the natural affine map $S(K_0pi).$ We give a condition under which $S(K_0pi)$ is an affine homeomorphism. At the same time, we discuss the relationship between semilocal rings and semiperfect rings by using the affine map $S(K_0pi).$
State space
$(K_0)$ group
pre-ordered group
affine map
2017
12
30
2507
2516
http://bims.iranjournals.ir/article_1191_e3849a0b67ab727cb48a0154db42ba3d.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Nonlinear Picone identities to Pseudo $p$-Laplace operator and applications
T.
Feng
M.
Yu
In this paper, we derive a nonlinear Picone identity to the pseudo p-Laplace operator, which contains some known Picone identities and removes a condition used in many previous papers. Some applications are given including a Liouville type theorem to the singular pseudo p-Laplace system, a Sturmian comparison principle to the pseudo p-Laplace equation, a new Hardy type inequality with weight and remainder term, a nonnegative estimate of the functional associated to pseudo p-Laplace equation.
Nonlinear Picone identity
pseudo $p$-Laplace equation
pseudo $p$-Laplace system
2017
12
01
2517
2530
http://bims.iranjournals.ir/article_1192_c065606badffd5fe4cb977c89c0de5c3.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
On the existence of Hilbert valued periodically correlated autoregressive processes
N.
Mohammadi Jouzdani
S.
Mahmoodi
A.
Parvardeh
In this paper we provide sufficient condition for existence of a unique Hilbert valued ($mathbb{H}$-valued) periodically correlated solution to the first order autoregressive model $X_{n}=rho _{n}X_{n-1}+Z_{n}$, for $nin mathbb{Z}$, and formulate the existing solution and its autocovariance operator. Also we specially investigate equivalent condition for the coordinate process $leftlangle X_{n},vrightrangle $, for arbitrary element $v$ in $mathbb{H}$, to satisfy in some autoregressive model. Finally, we extend our result to the autoregressive process with finite order.
Second order process
autoregressive process
periodically correlated process
Hilbert valued process
linear operator
2017
12
30
2531
2545
http://bims.iranjournals.ir/article_1195_5daaf15f086281252ac083bc654b1cfc.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Existence and convergence results for monotone nonexpansive type mappings in partially ordered hyperbolic metric spaces
R.
Shukla
R.
Pant
Z.
Kadelburg
H.
Nashine
We present some existence and convergence results for a general class of nonexpansive mappings in partially ordered hyperbolic metric spaces. We also give some examples to show the generality of the mappings considered herein.
Hyperbolic metric space
nonexpansive mapping
condition $(C)$
2017
12
30
2547
2565
http://bims.iranjournals.ir/article_1199_90b19cca8a330576f9bb4f3ff79cf8b8.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Characterization of finite $p$-groups by the order of their Schur multipliers ($t(G)=7$)
S.H.
Jafari
Let $G$ be a finite $p$-group of order $p^n$ and $|{mathcal M}(G)|=p^{frac{1}{2}n(n-1)-t(G)}$, where ${mathcal M}(G)$ is the Schur multiplier of $G$ and $t(G)$ is a nonnegative integer. The classification of such groups $G$ is already known for $t(G)leq 6$. This paper extends the classification to $t(G)=7$.
Schur multiplier
Nonabelian tensor square
p-Group
2017
12
30
2567
2576
http://bims.iranjournals.ir/article_1206_4a5ae568dd14e6cf4e4e5dfe4687c965.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
An extension of the Wedderburn-Artin Theorem
H.
Khabazian
In this paper we give conditions under which a ring is isomorphic to a structural matrix ring over a division ring.
Duo
artinian
distributive
uniserial
structural matrix
2017
12
30
2577
2583
http://bims.iranjournals.ir/article_1212_69f07f5026eb8ed76cc9168a2248eb14.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Recurrences and explicit formulae for the expansion and connection coefficients in series of the product of two classical discrete orthogonal polynomials
H.M.
Ahmed
Suppose that for an arbitrary function $f(x,y)$ of two discrete variables, we have the formal expansions. [f(x,y)=sumlimits_{m,n=0}^{infty }a_{m,n},P_{m}(x)P_{n}(y),] $$ x^{m}P_{j}(x)=sumlimits_{n=0}^{2m}a_{m,,n}(j)P_{j+m-n}(x),$$ we find the coefficients $b_{i,j}^{(p,q,ell ,,r)}$ in the expansion $$ x^{ell }y^{r},nabla _{x}^{p}nabla _{y}^{q},f(x,y)=x^{ell }y^{r}f^{(p,q)}(x,y) =sumlimits_{m,n=0}^{infty }a_{m,n}^{(p,q)},P_{m}(x)P_{n}(y),,,a_{m,n}^{(0,0)}=a_{m,n},$$ We give applications of these results in solving partial difference equations with varying polynomial coefficients, by reducing them to recurrence relations (difference equations) in the expansion coefficients of the solution.
Hahn
Meixner
Kravchuk and Charlier polynomials
expansion coefficient
recurrence relations
linear difference equations
connection coefficients
2017
12
30
2585
2615
http://bims.iranjournals.ir/article_1213_131b7669ec7a41ec353661475728792f.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Limits in modified categories of interest
K.
Emir
S.
Çetin
We firstly prove the completeness of the category of crossed modules in a modified category of interest. Afterwards, we define pullback crossed modules and pullback cat objects that are both obtained by pullback diagrams with extra structures on certain arrows. These constructions unify many corresponding results for the cases of groups, commutative algebras and can also be adapted to various algebraic structures.
Modified category of interest
crossed module
cat object
limit
2017
12
30
2617
2634
http://bims.iranjournals.ir/article_1222_e14591523a7f710c9325a6fd421f7fec.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Self-similar fractals and arithmetic dynamics
A.
Rastegar
The concept of self-similarity on subsets of algebraic varieties is defined by considering algebraic endomorphisms of the variety as `similarity' maps. Self-similar fractals are subsets of algebraic varieties which can be written as a finite and disjoint union of `similar' copies. Fractals provide a framework in which, one can unite some results and conjectures in Diophantine geometry. We define a well-behaved notion of dimension for self-similar fractals. We also prove a fractal version of Roth's theorem for algebraic points on a variety approximated by elements of a fractal subset. As a consequence, we get a fractal version of Siegel's theorem on finiteness of integral points on hyperbolic curves and a fractal version of Faltings' theorem on Diophantine approximation on abelian varieties.
Self-similarity
Diophantine approximation
arithmetic dynamics
2017
12
30
2635
2653
http://bims.iranjournals.ir/article_1246_b52e1ad99d6abc9c4958a326107bd224.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
7
Perturbation bounds for $g$-inverses with respect to the unitarily invariant norm
L.
Meng
Let complex matrices $A$ and $B$ have the same sizes. Using the singular value decomposition, we characterize the $g$-inverse $B^{(1)}$ of $B$ such that the distance between a given $g$-inverse of $A$ and the set of all $g$-inverses of the matrix $B$ reaches minimum under the unitarily invariant norm. With this result, we derive additive and multiplicative perturbation bounds of the nearest perturbed $g$-inverse. These results generalize and improve the existing results published recently to some extent.
$g$-inverse
additive perturbation bound
multiplicative perturbation bound
unitarily invariant norm
2017
12
30
2655
2662
http://bims.iranjournals.ir/article_1256_48f9f6287f956af831c7368cb1ae09b4.pdf