Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Stability of essential spectra of bounded linear operators
1057
1066
EN
F.
Abdmouleh
University of Sfax Tunisia
faical_abdmouleh@yahoo.fr
In this paper, we show the stability of Gustafson, Weidmann, Kato, Wolf, Schechter and Browder essential spectrum of bounded linear operators on Banach spaces which remain invariant under additive perturbations
belonging to a broad classes of operators $U$ such $gamma(U^m)
Fredholm operators,lower (respectively,upper) semi-Fredholm operators,essential spectra,compact operators
http://bims.iranjournals.ir/article_552.html
http://bims.iranjournals.ir/article_552_f745c234695fc9d63216bfacf853048a.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
A two-phase free boundary problem for a semilinear elliptic equation
1067
1086
EN
A.
Aghajani
Iran University of Science and Technology
aghajani@iust.ac.ir
In this paper we study a two-phase free boundary problem for a semilinear elliptic equation on a bounded domain $Dsubset mathbb{R}^{n}$ with smooth boundary. We give some results on the growth of solutions and characterize the free boundary points in terms of homogeneous harmonic polynomials using a fundamental result of Caffarelli and Friedman regarding the representation of functions whose Laplacians enjoy a certain inequality. We show that in dimension $n=2$, solutions have optimal growth at non-isolated singular points, and the same result holds for $ngeq3$ under an ($n-1$)-dimensional density condition. Furthermore, we prove that the set of points in the singular set that the solution does not have optimal growth is locally countably ($n-2$)-rectifiable.
Free boundary problems,optimal growth,regularity,singular set
http://bims.iranjournals.ir/article_553.html
http://bims.iranjournals.ir/article_553_0532226b244f965cdb1172d8caf97706.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Existence of a ground state solution for a class of $p$-laplace equations
1087
1095
EN
Y. H.
Deng
Department of Hengyang normal university
dengchen4032@126.com
According to a class of constrained
minimization problems, the Schwartz symmetrization process and the
compactness lemma of Strauss, we prove that there is a
nontrivial ground state solution for a class of $p$-Laplace
equations without the Ambrosetti-Rabinowitz condition.
Ground state solution,$p$-Laplace equation,minimization problem,the Schwartz symmetrization process
http://bims.iranjournals.ir/article_554.html
http://bims.iranjournals.ir/article_554_654d59a2d6d831ee91cb5555d9720659.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Theoretical results on the global GMRES method for solving generalized Sylvester matrix equations
1097
1117
EN
F.
Panjeh Ali Beik
Vali-Asr University of Rafsanjan
f.beik@vru.ac.ir
The global generalized minimum residual (Gl-GMRES)
method is examined for solving the generalized Sylvester matrix equation
[sumlimits_{i = 1}^q {A_i } XB_i = C.]
Some new theoretical results are elaborated for
the proposed method by employing the Schur complement.
These results can be exploited to establish new convergence properties
of the Gl-GMRES method for solving general (coupled) linear matrix
equations. In addition, the Gl-GMRES method for solving the generalized
Sylvester-transpose matrix equation is briefly studied.
Finally, some numerical experiments are presented to illustrate
the efficiently of the Gl-GMRES method for solving the general
linear matrix equations.
Linear matrix equation,Krylov subspace,global GMRES,Schur complement
http://bims.iranjournals.ir/article_555.html
http://bims.iranjournals.ir/article_555_436d6ad5ed75e3a57eae6a19e45899b6.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
On the elliptic curves of the form $ y^2=x^3-3px $
1119
1133
EN
H.
Daghigh
University of Kashan
hassan@kashanu.ac.ir
S.
Didari
University of Kashan
s.didari@grad.kashanu.ac.ir
By the Mordell-Weil theorem, the group of rational points on an elliptic curve over a number field is a finitely generated abelian group. There is no known algorithm for finding the rank of this group. This paper computes the rank of the family $ E_p:y^2=x^3-3px $ of elliptic curves, where p is a prime.
Elliptic Curves,Mordell-Weil group,Selmer Group,Birch and Swinnerton-Dyer conjecture
http://bims.iranjournals.ir/article_556.html
http://bims.iranjournals.ir/article_556_7a936719829fd98ff6277ef68f35035e.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Non existence of totally contact umbilical slant lightlike submanifolds of indefinite Sasakian manifolds
1135
1151
EN
R.
Sachdeva
School of Mathematics and Computer Applications,
Thapar University,
Patiala
rashmi.sachdeva86@gmail.com
R.
Kumar
University College of Engineering
Punjabi University, Patiala
dr_rk37c@yahoo.co.in
S.
Singh Bhatia
School of
Mathematics and Computer Applications,
Thapar University,
Patiala
ssbhatia@thapar.edu
We prove that there do not exist totally contact umbilical
proper slant lightlike submanifolds of indefinite Sasakian manifolds other than totally contact geodesic
proper slant lightlike submanifolds. We also prove that there do
not exist totally contact umbilical proper slant lightlike
submanifolds of indefinite Sasakian space forms.
Slant lightlike submanifolds,totally contact
umbilical lightlike submanifolds,totally contact geodesic lightlike
submanifolds,indefinite Sasakian manifolds
http://bims.iranjournals.ir/article_557.html
http://bims.iranjournals.ir/article_557_24ff97de6649946c62a7c349035161c9.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Maximal elements of $mathscr{F}_{C,theta}$-majorized mappings and applications to generalized games
1153
1167
EN
Y. M.
Du
Department of Mathematics,
Tianjin Polytechnic University
duyanmei@tjpu.edu.cn
In the paper, some new existence theorems of maximal elements for $mathscr{F}_{C,theta}$-mappings and $mathscr{F}_{C,theta}$-majorized mappings are established. As applications, some new existence theorems of equilibrium points for one-person games, qualitative games and generalized games are obtained. Our results unify and generalize most known results in recent literature.
Maximal elements,generalized games,$mathscr{F}_{C,theta}$-majorized mappings,$FC$-space
http://bims.iranjournals.ir/article_558.html
http://bims.iranjournals.ir/article_558_c9b400c9270fdd3a6552018a5e06fce5.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Lie-type higher derivations on operator algebras
1169
1194
EN
D.
Han
jiaozuo
dahai_hd@bit.edu.cn
Motivated by the intensive and powerful works concerning additive
mappings of operator algebras, we mainly study Lie-type higher
derivations on operator algebras in the current work. It is shown
that every Lie (triple-)higher derivation on some classical operator
algebras is of standard form. The definition of Lie $n$-higher
derivations on operator algebras and related potential research
topics are properly-posed at the end of this article.
Lie higher derivation,Lie triple higher derivation,operator algebra
http://bims.iranjournals.ir/article_559.html
http://bims.iranjournals.ir/article_559_422861332b6135b5ba4155ed2d6555f5.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Lower semicontinuity for parametric set-valued vector equilibrium-like problems
1195
1212
EN
J. W.
Chen
School of Mathematics and Statistics, Southwest University
j.w.chen713@163.com
A concept of weak $f$-property for a set-valued mapping is introduced, and then under some suitable assumptions, which do not involve any information
about the solution set, the lower semicontinuity of the solution mapping to
the parametric
set-valued vector equilibrium-like problems are derived by using a density result and scalarization method, where the
constraint set $K$ and a set-valued mapping $H$ are perturbed by
different parameters.
Lower semicontinuity,parametric set-valued vector equilibrium-like problem,weak $f$-property,positive proper efficient solution
http://bims.iranjournals.ir/article_560.html
http://bims.iranjournals.ir/article_560_0803382a985417ff20dedff0e60788cf.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Groups in which every subgroup has finite index in its Frattini closure
1213
1226
EN
F.
De Giovanni
Università di Napoli Federico II
degiovan@unina.it
D.
Imperatore
Università di Napoli "Federico II"
Dipartimento di Matematica e Applicazioni
diana.imperatore@unina.it
In 1970, Menegazzo [Gruppi nei quali ogni sottogruppo e intersezione di sottogruppi massimali, Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur. 48 (1970), 559--562.] gave a complete description of the structure of soluble $IM$-groups, i.e., groups in which every subgroup can be obtained as intersection of maximal subgroups. A group $G$ is said to have the $FM$-property if every subgroup of $G$ has finite index in the intersection $hat X$ of all maximal subgroups of $G$ containing $X$. The behaviour of (generalized) soluble $FM$-groups is studied in this paper. Among other results, it is proved that if~$G$ is a (generalized) soluble group for which there exists a positive integer $k$ such that $|hat X:X|leq k$ for each subgroup $X$, then $G$ is finite-by-$IM$-by-finite, i.e., $G$ contains a finite normal subgroup $N$ such that $G/N$ is a finite extension of an $IM$-group.
Maximal subgroup,Frattini closure,$FM$-group
http://bims.iranjournals.ir/article_561.html
http://bims.iranjournals.ir/article_561_3a8e1901acbb88df60bd42b42c8fb15d.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
On $L_1$-weak ergodicity of nonhomogeneous continuous-time Markov processes
1227
1242
EN
F.
Mukhamedov
International Islamic University of Malaysia
far75m@yandex.ru
In the present paper we investigate the $L_1$-weak ergodicity of
nonhomogeneous continuous-time Markov processes with general state
spaces. We provide a necessary and sufficient condition for such
processes to satisfy the $L_1$-weak ergodicity. Moreover, we apply
the obtained results to establish $L_1$-weak ergodicity of quadratic
stochastic processes.
Weak ergodicity,$L_1$-weak ergodicity,
nonhomogeneous Markov process, quadratic
stochastic process
http://bims.iranjournals.ir/article_562.html
http://bims.iranjournals.ir/article_562_27c5feba62636d0718b0551a9db010f6.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
On finite $X$-decomposable groups for $X={1, 2, 3, 4}$
1243
1262
EN
X.
Guo
Shanghai University
xyguo@shu.edu.cn
R.
Chen
Shanghai University
fang119128@126.com
Let $mathcal {N}_G$ denote the set of all proper
normal subgroups of a group $G$ and $A$ be an element of $mathcal
{N}_G$. We use the notation $ncc(A)$ to denote the number of
distinct $G$-conjugacy classes contained in $A$ and also $mathcal
{K}_G$ for the set ${ncc(A) | Ain mathcal {N}_G}$. Let $X$ be
a non-empty set of positive integers. A group $G$ is said to be
$X$-decomposable, if $mathcal {K}_G=X$. In this paper we give a
classification of finite $X$-decomposable groups for $X={1, 2, 3,
4}$.
$n$-decomposable,$X$-decomposable,$G$-conjugacy classes
http://bims.iranjournals.ir/article_563.html
http://bims.iranjournals.ir/article_563_998ce6654cd16ec63477cd8cb2541111.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Baer's lower nilradical and classical prime submodules
1263
1274
EN
E.
Yılmaz
Abant İzzet Baysal University
yilmaz_e2@ibu.edu.tr
S.
Kılıçarslan Cansu
Istanbul Technical University
sibelkcansu@gmail.com
Let $N$ be a submodule of a module $M$ and a minimal primary decomposition of $N$ is known. A formula to compute Baer's lower nilradical of $N$ is given. The relations between classical prime submodules and their nilradicals are investigated. Some situations in which semiprime submodules can be written as finite intersection of classical prime submodule are stated.
Envelopes,Nilradical,classical prime submodules,semi-prime submodules
http://bims.iranjournals.ir/article_564.html
http://bims.iranjournals.ir/article_564_7fdaebb33e052f3690d592f01b7f3311.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Convergence analysis of spectral Tau method for fractional Riccati differential equations
1275
1290
EN
P.
Mokhtary
Muslim
mokhtary.payam@gmail.com
F.
Ghoreishi
muslim
ghoreishif@kntu.ac.ir
In this paper, a spectral Tau method for solving fractional Riccati
differential equations is considered. This technique describes
converting of a given fractional Riccati differential equation to a
system of nonlinear algebraic equations by using some simple
matrices. We use fractional derivatives in the Caputo form.
Convergence analysis of the proposed method is given and rate of
convergence is established in the weighted $L^2-$norm. Numerical
results are presented to confirm the high accuracy of the
method.
Fractional Riccati differential equations,Caputo derivative,spectral Tau method
http://bims.iranjournals.ir/article_565.html
http://bims.iranjournals.ir/article_565_640b209b5b3935e605fe16785504abcc.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Nilpotent groups with three conjugacy classes of non-normal subgroups
1291
1300
EN
H.
Mousavi
Department of Mathematics, University of Tabriz' P.O.Box 51666-17766
mousavi.hamid@gmail.com
Let $G$ be a finite group and $nu(G)$ denote the number of conjugacy classes of non-normal subgroups of $G$. In this paper, all nilpotent groups $G$ with $nu(G)=3$ are classified.
Non-normal subgroup,conjugacy class,nilpotent group
http://bims.iranjournals.ir/article_566.html
http://bims.iranjournals.ir/article_566_60fb1fd6f6e8ad3f51b8c37257f7424a.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
Existence and multiplicity of nontrivial solutions for $p$-Laplacian system with nonlinearities of concave-convex type and sign-changing weight functions
1301
1326
EN
S.
Khademloo
Department of basic sciences, babol noushirvani university of technology, babol, Iran
s.khademloo@nit.ac.ir
S.
Khanjany Ghazi
Babol university of technology
s.khanjany@gmail.com
This paper is concerned with the existence of multiple positive
solutions for a quasilinear elliptic system involving concave-convex
nonlinearities
and sign-changing weight functions. With the help of the Nehari manifold and Palais-Smale condition,
we prove that the system has at least two nontrivial positive
solutions, when the pair of parameters $(lambda,mu)$ belongs to a certain subset of $mathbb{R}^2$.
variational methods,Nehari manifold,Dirichlet boundary condition,sign-changing weight functions
http://bims.iranjournals.ir/article_567.html
http://bims.iranjournals.ir/article_567_d5399e64cb0da186a30a56ce28cb3c50.pdf
Iranian Mathematical Society (IMS)
Bulletin of the Iranian Mathematical Society
1017-060X
1735-8515
40
5
2014
10
01
ILU and IUL factorizations obtained from forward and backward factored approximate inverse algorithms
1327
1346
EN
A.
Rafiei
Hakim Sabzevari University
rafiei.am@gmail.com
In this paper, an efficient dropping criterion has been used to compute the IUL factorization obtained from Backward Factored APproximate INVerse (BFAPINV) and ILU factorization obtained from Forward Factored APproximate INVerse (FFAPINV) algorithms. We use different drop tolerance parameters to compute the preconditioners. To study the effect of such a dropping on the quality of the ILU and IUL factorizations, we have used the preconditioners as the right preconditioners for several linear systems and then, the Krylov subspace methods have been used to solve the preconditioned systems. To avoid storing matrix $A$ in two CSR and CSC formats, the linked lists trick has been used in the implementations. As the preprocessing, the multilevel nested dissection reordering has also been used.
ILU factorization,IUL factorization,forward $FAPINV$ process,backward $FAPINV$ process,linked lists trick
http://bims.iranjournals.ir/article_568.html
http://bims.iranjournals.ir/article_568_954d6365d35f2491fdc177d5310770af.pdf