Bulletin of the Iranian Mathematical Society
text
article
2017
eng
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
http://bims.iranjournals.ir/article_1131_67225b7753fc77e8ce2dbd54c753e207.pdf
A comprehensive unified model of structural and reduced form type for defaultable fixed income bonds
H.-C.
O
Faculty of Mathematics, Kim Il Sung University, Taesong District, Pyongyang, D. P. R. Korea.
author
J.-J.
Jo
Faculty of Mathematics, Kim Il Sung University, Taesong District, Pyongyang, D. P. R. Korea.
author
S.-Y.
Kim
Faculty of Mathematics, Kim Il Sung University, Taesong District, Pyongyang, D. P. R. Korea.
author
S.-G.
Jon
Faculty of Mathematics, Kim Il Sung University, Taesong District, Pyongyang, D. P. R. Korea.
author
text
article
2017
eng
The aim of this paper is to generalize the comprehensive structural model for defaultable fixed income bonds (considered in R. Agliardi, A comprehensive structural model for defaultable fixed-income bondsو Quant. Finance 11 (2011), no. 5, 749--762.) into a comprehensive unified model of structural and reduced form models. In our model the bond holders receive the deterministic coupon at predetermined coupon dates and the face value (debt) and the coupon at the maturity as well as the effect of government taxes which are paid on the proceeds of an investment in bonds is considered. The expected default event occurs when the equity value is not enough to pay coupon or debt at the coupon dates or maturity and an unexpected default event can occur at any time interval with the probability of given default intensity. We consider the model and pricing formula for equity value and using it calculate expected default barrier. Then we provide pricing model and formula for defaultable corporate bonds with discrete coupons, and consider the duration and the effect of the government taxes.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
575
599
http://bims.iranjournals.ir/article_1109_0db0b4521c266154ab5646b7363dcf39.pdf
Solvability of an impulsive boundary value problem on the half-line via critical point theory
M.
Briki
Laboratory of Fixed Point Theory and Applications, Ecole Normale Superieure,
Kouba, Algiers, Algeria.
author
S.
Djebali
Department of Mathematics, Faculty of Sciences,
Al Imam Mohammad Ibn Saud Islamic University (IMSIU). P.O. Box 90950, Riyadh 11623, Saudi Arabia
and Department of Mathematics, Ecole Normale Superieure, Kouba.
author
T.
Moussaoui
Laboratory of Fixed Point Theory and Applications, Ecole Normale Superieure,
Kouba, Algiers, Algeria.
author
text
article
2017
eng
In this paper, an impulsive boundary value problem on the half-line is considered and existence of solutions is proved using Minimization Principal and Mountain Pass Theorem.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
601
615
http://bims.iranjournals.ir/article_951_3f4b6ba65f5bea2d1d1ee70c0679b355.pdf
Weak convergence theorems for symmetric generalized hybrid mappings in uniformly convex Banach spaces
F.
Moradlou
Department of Mathematics, Sahand University of Technology, Tabriz, Iran.
author
S.
Alizadeh
Department of Mathematics, Marand Branch, Islamic Azad University, Marand, Iran.
author
text
article
2017
eng
In this paper, we prove some theorems related to properties of generalized symmetric hybrid mappings in Banach spaces. Using Banach limits, we prove a fixed point theorem for symmetric generalized hybrid mappings in Banach spaces. Moreover, we prove some weak convergence theorems for such mappings by using Ishikawa iteration method in a uniformly convex Banach space.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
617
627
http://bims.iranjournals.ir/article_952_cc093e273a76ab5a2ac62180f5bf2eb6.pdf
Uniqueness of meromorphic functions ans Q-differential polynomials sharing small functions
N.V.
Thin
Department of Mathematics, Thai Nguyen University of Education, Luong Ngoc Quyen Street, Thai Nguyen City, Viet Nam.
author
text
article
2017
eng
The paper concerns interesting problems related to the field of Complex Analysis, in particular, Nevanlinna theory of meromorphic functions. We have studied certain uniqueness problem on differential polynomials of meromorphic functions sharing a small function. Outside, in this paper, we also consider the uniqueness of $q-$ shift difference - differential polynomials of meromorphic functions sharing small function or a set in the complex plane.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
629
647
http://bims.iranjournals.ir/article_953_629162e9ca21b08d9bf8cb82e7b9d9ea.pdf
Coordinate finite type invariant surfaces in Sol spaces
D.W.
Yoon
Department of
Mathematics Education and RINS, Gyeongsang National University, Jinju, 660-701, South Korea.
author
text
article
2017
eng
In the present paper, we study surfaces invariant under the 1-parameter subgroup in Sol space $\rm Sol_3$. Also, we characterize the surfaces in $\rm Sol_3$ whose coordinate functions of an immersion of the surface are eigenfunctions of the Laplacian $\Delta$ of the surface.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
649
658
http://bims.iranjournals.ir/article_954_672eb342b587b6c02c016091e7593cad.pdf
On non-normal non-abelian subgroups of finite groups
C.
Zhang
School of Mathematics and Information Science,
Yantai University, Yantai 264005, China.
author
text
article
2017
eng
In this paper we prove that a finite group $G$ having at most three conjugacy classes of non-normal non-abelian proper subgroups is always solvable except for $G\cong{\rm{A_5}}$, which extends Theorem 3.3 in [Some sufficient conditions on the number of non-abelian subgroups of a finite group to be solvable, Acta Math. Sinica (English Series) 27 (2011) 891--896.]. Moreover, we show that a finite group $G$ with at most three same order classes of non-normal non-abelian proper subgroups is always solvable except for $G\cong{A_5}$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
659
663
http://bims.iranjournals.ir/article_955_337a7def7f393b8d74b7c0e4c79047e1.pdf
Solitons for nearly integrable bright spinor Bose-Einstein condensate
F.
Ahmadi Zeidabadi
Vali-E-Asr University of Rafsanjan, Rafsanjan, Iran
Present Affiliation: Department of Mathematics, Sirjan University of Technology, Sirjan, Iran.
author
S.M.
Hoseini
Vali-E-Asr University of Rafsanjan, Rafsanjan, Iran.
author
text
article
2017
eng
Using the explicit forms of eigenstates for linearized operator related to a matrix version of Nonlinear Schrödinger equation, soliton perturbation theory is developed for the $F=1$ bright spinor Bose-Einstein condensates. A small disturbance of the integrability condition can be considered as a small correction to the integrable equation. By choosing appropriate perturbation, the soliton solution for small deviation from the integrability condition is found. Numerical simulations exhibit good agreement with analytical results.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
665
681
http://bims.iranjournals.ir/article_956_e5d47cf69627abce678d9f542ff5b1f6.pdf
Mathematical modeling, analysis and simulation of Ebola epidemics
T.
Wetere Tulu
Harbin Institute of Technology, Department of Mathematics, Harbin, China
and Addis Ababa Science and Technology University, Addis Ababa, Ethiopia.
author
T.
Boping
Harbin Institute of Technology, Department of Mathematics, Harbin, China.
author
text
article
2017
eng
Mathematical models are the most important tools in epidemiology to understand previous outbreaks of diseases and to better understand the dynamics of how infections spread through populations. Many existing models closely approximate historical disease patterns. This article investigates the mathematical model of the deadly disease with severe and uncontrollable bleeding, Ebola which is currently becoming the headache of the whole world though effort to control is undergoing. In this paper a new mathematical model of the Ebola epidemic is built. Besides, the basic reproduction number is calculated and the stability of both disease free and endemic equilibrium is proved. Finally, numerical simulations are executed to further consolidate the analysis of the deadly disease Ebola.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
683
693
http://bims.iranjournals.ir/article_957_813ca39b1e7c5ffd53b4eddc4652ed6a.pdf
On 5-dimensional 2-step homogeneous randers nilmanifolds of Douglas type
M.
Nasehi
Department of Mathematical Sciences, Isfahan University of Technology,
Isfahan, 84156-83111, Iran.
author
text
article
2017
eng
In this paper we first obtain the non-Riemannian Randers metrics of Douglas type on two-step homogeneous nilmanifolds of dimension five. Then we explicitly give the flag curvature formulae and the $S$-curvature formulae for the Randers metrics of Douglas type on these spaces. Moreover, we prove that the only simply connected five-dimensional two-step homogeneous Randers nilmanifolds of Douglas type which are Ricci-quadratic have a three-dimensional centre. We also prove that all simply connected five-dimensional two-step homogeneous Randers nilmanifolds of Douglas type are never weakly symmetric. The existence of homogeneous Randers spaces of Douglas type with vanishing $S$-curvature which are never g.o. Finsler spaces is also proved and some examples of locally projectively flat Finsler spaces are also obtained.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
695
706
http://bims.iranjournals.ir/article_958_d46cf0cb3a9474148048d3c9a1b8fe85.pdf
Theory of hybrid differential equations on time scales
S.
Sun
School of Mathematical Sciences, University of Jinan, Jinan, Shandong 250022, P.R. China.
author
Y.
Zhao
School of Mathematical Sciences, University of Jinan, Jinan, Shandong 250022, P.R. China.
author
P.
Zhao
School of Electrical Engineering, University of Jinan, Jinan, Shandong 250022, P.R. China.
author
Z.
Han
School of Electrical Engineering, University of Jinan, Jinan, Shandong 250022, P.R. China.
author
text
article
2017
eng
In this paper, we develop the theory of hybrid differential equations on time scales. An existence theorem for hybrid differential equations on time scales is given under Lipschitz conditions. Some fundamental fractional differential inequalities are also established which are utilized to prove the existence of extremal solutions. Necessary tools are considered and the comparison principle is proved which will be useful for further study of qualitative behavior of solutions. Our results in this paper extend and improve some known results.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
707
725
http://bims.iranjournals.ir/article_959_3495a2c9d4cf4c659753aca717c9729b.pdf
Strongly k-spaces
S.
Ersoy
Department of Mathematics, Faculty of Arts and Sciences,
Sakarya University, Sakarya, 54187, Turkey.
author
İ.
İnce
Department of Mathematics, Faculty of Arts and Sciences,
Sakarya University, Sakarya, 54187, Turkey.
author
M.
Bilgin
Department of Mathematics, Faculty of Arts and Sciences,
Sakarya University, Sakarya, 54187 TURKEY
author
text
article
2017
eng
In this paper, we introduce the notion of strongly $k-$spaces (with the weak (=finest) pre-topology generated by their strongly compact subsets). We characterize the strongly $k-$spaces and investigate the relationships between preclosedness, locally strongly compactness, pre-first countableness and being strongly $k-$space.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
727
734
http://bims.iranjournals.ir/article_960_fddf1523fdfc77a3cfe52c9a3c6ce4d6.pdf
On a class of locally projectively flat Finsler metrics
X.H.
Mo
Key Laboratory of Pure and Applied Mathematics,
School of Mathematical Sciences, Peking University,
Beijing 100871, China.
author
H.M.
Zhu
College of Mathematics and Information Science,
Henan Normal University,
Xinxiang, 453007, China.
author
text
article
2017
eng
In this paper we study Finsler metrics with orthogonal invariance. We find a partial differential equation equivalent to these metrics being locally projectively flat. Some applications are given. In particular, we give an explicit construction of a new locally projectively flat Finsler metric of vanishing flag curvature which differs from the Finsler metric given by Berwald in 1929.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
735
746
http://bims.iranjournals.ir/article_961_b53c921cf2d21caa37f214470b8f3e56.pdf
Frattini supplements and Frat- series
Y.
Aydın
Faculty of Arts and Sciences, Department of Mathematics, Ondokuz Mayis University, Samsun, Turkey.
author
A.
Pancar
Faculty of Arts and Sciences, Department of Mathematics, Ondokuz Mayis University, Samsun, Turkey.
author
text
article
2017
eng
In this study, Frattini supplement subgroup and Frattini supplemented group are defined by Frattini subgroup. By these definitions, it's shown that finite abelian groups are Frattini supplemented and every conjugate of a Frattini supplement of a subgroup is also a Frattini supplement. A group action of a group is defined over the set of Frattini supplements of a normal subgroup of the group by conjugation and in this study new characterization of primitivity of groups has obtained in terms of Frattini supplemented groups by this action. Moreover, Frat-series of a group is defined based on Frattini supplements of normal subgroups of the group and it is shown that subgroups and factor groups of groups with Frat-series also have Frat-series under some special conditions. Furthermore, we determined a characterization of soluble groups which have Frat-series.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
747
753
http://bims.iranjournals.ir/article_962_408ef6dcf6b085e43a37f5b92e2f4595.pdf
Finite groups all of whose proper centralizers are cyclic
S.M.
Jafarian Amiri
Department of Mathematics, Faculty of Sciences, University of Zanjan, P.O. Box 45371-38791, Zanjan, Iran.
author
H.
Rostami
Department of Mathematics, Faculty of Sciences, University of Zanjan, P.O. Box 45371-38791, Zanjan, Iran.
author
text
article
2017
eng
A finite group $G$ is called a $CC$-group ($G\in CC$) if the centralizer of each noncentral element of $G$ is cyclic. In this article we determine all finite $CC$-groups.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
755
762
http://bims.iranjournals.ir/article_963_39f77437f2f3e5d47eabce3d4736d817.pdf
The concentration function problem for $G$-spaces
M.S.
Mojahedi Moakhar
Department of Mathematics, Tarbiat Modares University, Tehran 14115-134, Iran.
author
text
article
2017
eng
In this note, we consider the concentration function problem for a continuous action of a locally compact group $G$ on a locally compact Hausdorff space $X$. We prove a necessary and sufficient condition for the concentration functions of a spread-out irreducible probability measure $\mu$ on $G$ to converge to zero.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
763
769
http://bims.iranjournals.ir/article_964_1896a9ee98295b306dd85cddf8f84de2.pdf
A characterization of curves in Galilean 4-space $G_4$
G.
Öztürk
Kocaeli University, Art and Science Faculty, Department of Mathematics,
Kocaeli, Turkey.
author
S.
Büyükkütük
Kocaeli University, Art and Science Faculty, Department of Mathematics,
Kocaeli, Turkey.
author
İ.
Kişi
Kocaeli University, Art and Science Faculty, Department of Mathematics,
Kocaeli, Turkey.
author
text
article
2017
eng
In the present study, we consider a regular curve in Galilean $4$-space $\mathbb{G}_{4}$ whose position vector is written as a linear combination of its Frenet vectors. We characterize such curves in terms of their curvature functions. Further, we obtain some results of rectifying, constant ratio, $T$-constant and $N$-constant curves in $\mathbb{G}_{4}$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
771
780
http://bims.iranjournals.ir/article_965_86d3476c41f085716f438f92ec30c419.pdf
Unmixed $r$-partite graphs
R.
Zaare-Nahandi
Department of Mathematics, Institute for Advanced Studies
in Basic Science (IASBS), P.O. Box 45195-1159, Zanjan, Iran.
author
R.
Jafarpour-Golzari
Department of Mathematics, Institute for Advanced Studies
in Basic Science (IASBS), P.O. Box 45195-1159, Zanjan, Iran.}
author
text
article
2017
eng
Unmixed bipartite graphs have been characterized by Ravindra and Villarreal independently. Our aim in this paper is to characterize unmixed $r$-partite graphs under a certain condition, which is a generalization of Villarreal's theorem on bipartite graphs. Also, we give some examples and counterexamples in relevance to this subject.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
781
787
http://bims.iranjournals.ir/article_966_bec072d93e37ac6373af70963acf6ac6.pdf
On boundary value problem for fractional differential equations
M.R.
Hamidi
Department of Mathematics, Faculty of Sciences, Razi University, 67149 Kermanshah, Iran.
author
N.
Nyamoradi
Department of Mathematics, Faculty of Sciences, Razi University, 67149 Kermanshah, Iran.
author
text
article
2017
eng
In this paper, we study the existence of solutions for a fractional boundary value problem. By using critical point theory and variational methods, we give some new criteria to guarantee that the problems have at least one solution and infinitely many solutions.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
789
805
http://bims.iranjournals.ir/article_967_d381663683864b185eb06d06ebb29f7e.pdf
Almost valuation rings
R.
Jahani-Nezhad
Department of Mathematics, University
of Kashan, P.O. Box 8731751167, Kashan, Iran.
author
F.
Khoshayand
Department of Mathematics, University
of Qom, P.O. Box 3716146611, Qom, Iran.
author
text
article
2017
eng
The aim of this paper is to generalize the notion of almost valuation domains to arbitrary commutative rings. Also, we consider relations between almost valuation rings and pseudo-almost valuation rings. We prove that the class of almost valuation rings is properly contained in the class of pseudo-almost valuation rings. Among the properties of almost valuation rings, we show that a quasilocal ring $R$ with regular maximal ideal $M$ is a pseudo-almost valuation ring if and only if $V = (M : M)$ is an almost valuation ring with maximal ideal ${\rm Rad}_V(M)$. Furthermore, we show that pseudo-almost valuationrings are precisely the pullbacks of almost valuation rings.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
807
816
http://bims.iranjournals.ir/article_970_fa53dd75a192135fa5fdfae32180d7f6.pdf
W-convergence of the proximal point algorithm in complete CAT(0) metric spaces
S.
Ranjbar
Department of Mathematics, College of Sciences, Higher Education Center of Eghlid, Eghlid, Iran.
author
text
article
2017
eng
In this paper, we generalize the proximal point algorithm to complete CAT(0) spaces and show that the sequence generated by the proximal point algorithm $w$-converges to a zero of the maximal monotone operator. Also, we prove that if $f: X\rightarrow ]-\infty, +\infty]$ is a proper, convex and lower semicontinuous function on the complete CAT(0) space $X$, then the proximal point algorithm $w$-converges to a zero of the subdifferential of $f$, i.e., a minimizer of $f$. Some strong convergence results (convergence in metric) are also presented with additional assumptions on the monotone operator and the convex function $f$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
817
834
http://bims.iranjournals.ir/article_971_82f5acff6dbe281bad8d1a4e7301a6f6.pdf
On quasi $P$-spaces and their applications in submaximal and nodec spaces
A.
R. Aliabad
Department of Mathematics, Chamran University, Ahwaz, Iran.
author
V.
Bagheri
Department of Mathematics, Chamran University, Ahwaz, Iran.
author
M.
Karavan Jahromi
Department of Mathematics, Persian Gulf University, Boushehr, Iran.
author
text
article
2017
eng
A topological space is called submaximal if each of its dense subsets is open and is called nodec if each of its nowhere dense ea subsets is closed. Here, we study a variety of spaces some of which have already been studied in $C(X)$. Among them are, most importantly, quasi $P$-spaces and pointwise quasi $P$-spaces. We obtain some new useful topological characterizations of quasi $P$-spaces and pointwise quasi $P$-spaces. Consequently, we obtain a close relation between these latter spaces and submaximal and nodec spaces.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
835
852
http://bims.iranjournals.ir/article_972_c47563ae70da99592883044ab83cfb5c.pdf
Some results on the symmetric doubly stochastic inverse eigenvalue problem
W.-R.
Xu
Department of Mathematics, Shanghai Key Laboratory of Pure Mathematics and Mathematical Practice, East China Normal University, Shanghai, 200241, P. R. China.
author
G.-L.
Chen
Department of Mathematics, Shanghai Key Laboratory of Pure Mathematics and Mathematical Practice, East China Normal University, Shanghai, 200241, P. R. China.
author
text
article
2017
eng
The symmetric doubly stochastic inverse eigenvalue problem (hereafter SDIEP) is to determine the necessary and sufficient conditions for an $n$-tuple $\sigma=(1,\lambda_{2},\lambda_{3},\ldots,\lambda_{n})\in \mathbb{R}^{n}$ with $|\lambda_{i}|\leq 1,~i=1,2,\ldots,n$, to be the spectrum of an $n\times n$ symmetric doubly stochastic matrix $A$. If there exists an $n\times n$ symmetric doubly stochastic matrix $A$ with $\sigma$ as its spectrum, then the list $\sigma$ is s.d.s. realizable, or such that $A$ s.d.s. realizes $\sigma$. In this paper, we propose a new sufficient condition for the existence of the symmetric doubly stochastic matrices with prescribed spectrum. Finally, some results about how to construct new s.d.s. realizable lists from the known lists are presented.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
853
865
http://bims.iranjournals.ir/article_973_5217f95bb88349cb243d3f654f570e95.pdf
On the type of conjugacy classes and the set of indices of maximal subgroups
J.
Shi
School of Mathematics and Information Science,
Yantai University, Yantai 264005, China.
author
Z.
Wu
Xingjian College of Science and Liberal Arts, Guangxi University, Nanning 530004, China.
author
R.
Hou
School of Mathematics and Information Science,
Yantai University, Yantai 264005, China.
author
text
article
2017
eng
Let $G$ be a finite group. By $MT(G)=(m_1,\cdots,m_k)$ we denote the type of conjugacy classes of maximal subgroups of $G$, which implies that $G$ has exactly $k$ conjugacy classes of maximal subgroups and $m_1,\ldots,m_k$ are the numbers of conjugates of maximal subgroups of $G$, where $m_1\leq\cdots\leq m_k$. In this paper, we give some new characterizations of finite groups by the type of conjugacy classes of maximal subgroups. By $\pi_t(G)$ we denote the set of indices of all maximal subgroups of $G$. We also investigate the influence of the set of indices of all maximal subgroups on the structure of finite groups.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
867
874
http://bims.iranjournals.ir/article_974_3b6f8402dda5e66b81d06f6e49045069.pdf
On reducibility of weighted composition operators
M. R.
Azimi
Department of Mathematics,
University of Maragheh,
Maragheh,
Iran.
author
M. R.
Jabbarzadeh
faculty of mathematical sciences, university of tabriz, p. o. box: 5166615648, tabriz,
author
M.
Jafari Bakhshkandi
faculty of mathematical sciences, university of tabriz, p. o. box: 5166615648, tabriz,
author
text
article
2017
eng
In this paper, we study two types of the reducing subspaces for the weighted composition operator $W: f\rightarrow u\cdot f\circ \varphi$ on $L^2(\Sigma)$. A necessary and sufficient condition is given for $W$ to possess the reducing subspaces of the form $L^2(\Sigma_B)$ where $B\in \Sigma_{sigma(u)}$. Moreover, we pose some necessary and some sufficient conditions under which the subspaces of the form $L^2(\mathcal{A})$ reduce $W$. All of these are basically discussed by using the conditional expectation properties. To explain the results some examples are then presented.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
875
883
http://bims.iranjournals.ir/article_981_31b5913fd99bd8a7884acd03213dd58a.pdf
Almost specification and renewality in spacing shifts
D.
Ahmadi Dastjerdi
Department of Pure Mathematics,
Faculty of Mathematical Sciences,
University of Guilan, Iran.
author
M.
Dabbaghian Amiri
Department of Pure Mathematics,
Faculty of Mathematical Sciences, University of Guilan, Iran.
author
text
article
2017
eng
Let $(\Sigma_P,\sigma_P)$ be the space of a spacing shifts where $P\subset \mathbb{N}_0=\mathbb{N}\cup\{0\}$ and $\Sigma_P=\{s\in\{0,1\}^{\mathbb{N}_0}: s_i=s_j=1 \mbox{ if } |i-j|\in P \cup\{0\}\}$ and $\sigma_P$ the shift map. We will show that $\Sigma_P$ is mixing if and only if it has almost specification property with at least two periodic points. Moreover, we show that if $h(\sigma_P)=0$, then $\Sigma_P$ is almost specified and if $h(\sigma_P)>0$ and $\Sigma_P$ is almost specified, then it is weak mixing. Also, some sufficient conditions for a coded $\Sigma_P$ being renewal or uniquely decipherable is given. At last we will show that here are only two conjugacies from a transitive $\Sigma_P$ to a subshift of $\{0,1\}^{\mathbb{N}_0}$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
885
896
http://bims.iranjournals.ir/article_978_a06a483757e387013b6d5bbf696db11a.pdf
Double derivations of n-Lie algebras
R.
Bai
College of Mathematics and Information Science,
Hebei University, Baoding 071002, P.R. China.
author
Y.
Gao
College of Mathematics and Information Science,
Hebei University, Baoding 071002, P.R. China.
author
Y.
Zhang
College of Mathematics and Information Science,
Hebei University, Baoding 071002, P.R. China.
author
Z.
Li
College of Mathematics and Information Science,
Hebei University, Baoding 071002, P.R. China.
author
text
article
2017
eng
After introducing double derivations of $n$-Lie algebra $L$ we describe the relationship between the algebra $\mathcal D(L)$ of double derivations and the usual derivation Lie algebra $\mathcal Der(L)$. In particular, we prove that the inner derivation algebra $ad(L)$ is an ideal of the double derivation algebra $\mathcal D(L)$; we also show that if $L$ is a perfect $n$-Lie algebra with certain constraints on the base field then the centralizer of $ad(L)$ in $\mathcal D(L)$ is trivial and $\mathcal D(L)$ is centerless. In addition, we obtain that for every perfect $n$-Lie algebra $L$ with zero center, the triple derivations of the derivation algebra $\mathcal Der(L)$ are exactly the derivations of $\mathcal Der(L)$, and the triple derivations of the inner derivation algebra $ad(L)$ are precisely the derivations of $ad(L)$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
897
910
http://bims.iranjournals.ir/article_980_435becbcb5d7a8ea49d428daf9a529cf.pdf
Modules for which every non-cosingular submodule is a summand
Y.
Talebi
Department of Mathematics, Faculty of Mathematical Sciences,
University of Mazandaran, Babolsar, Iran.
author
M.
Hosseinpour
Department of Mathematics, Faculty of Mathematical Sciences,
University of Mazandaran, Babolsar, Iran.
author
A.R.
Moniri Hamzekolaee
Department of Mathematics, Faculty of Mathematical Sciences,
University of Mazandaran, Babolsar, Iran.
author
text
article
2017
eng
A module $M$ is lifting if and only if $M$ is amply supplemented and every coclosed submodule of $M$ is a direct summand. In this paper, we are interested in a generalization of lifting modules by removing the condition"amply supplemented" and just focus on modules such that every non-cosingular submodule of them is a summand. We call these modules NS. We investigate some general properties of NS-modules. Several examples are provided to separate different concepts. It is shown that every non-cosingular NS-module is a direct sum of indecomposable modules. We also discuss on finite direct sums of NS-modules.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
911
922
http://bims.iranjournals.ir/article_983_bb395f9f3798907e63a6206e886b8c18.pdf
A note on blow-up in parabolic equations with local and localized sources
B.
Liu
College of Science, China University of Petroleum, Qingdao 266580, Shandong Province, P.R. China; Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, IN 46556, USA.
author
F.
Li
College of Science, China University of Petroleum, Qingdao 266580, Shandong Province, P.R. China; Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, IN 46556, USA.
author
text
article
2017
eng
This note deals with the systems of parabolic equations with local and localized sources involving $n$ components. We obtained the exponent regions, where $k\in \{1,2,\cdots,n\}$ components may blow up simultaneously while the other $(n-k)$ ones still remain bounded under suitable initial data. It is proved that different initial data can lead to different blow-up phenomena even in the same exponent regions, and moreover, different blow-up mechanism leads to different blow-up rates and blow-up sets.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
923
942
http://bims.iranjournals.ir/article_984_3557e83881f711d9b5eb44a8204b265f.pdf
Simple axiomatization of reticulations on residuated lattices
M.
Kondo
Department of mathematics, School of System Design and Technolodgy, Tokyo Denki University, Japan.
author
text
article
2017
eng
We give a simple and independent axiomatization of reticulations on residuated lattices, which were axiomatized by five conditions in [C. Mureşan, The reticulation of a residuated lattice, Bull. Math. Soc. Sci. Math. Roumanie 51 (2008), no. 1, 47--65]. Moreover, we show that reticulations can be considered as lattice homomorphisms between residuated lattices and bounded distributive lattices. Consequently, the result proved by Muresan in 2008, for any two reticulattions $(L_1, \lambda_1), (L_2, \lambda_2)$ of a residuated lattice $X$ there exists an isomorphism $f: L_1 \to L_2$ such that $f\circ \lambda_1 = \lambda_2$, can be considered as a homomorphism theorem.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
943
949
http://bims.iranjournals.ir/article_985_6b7c6fb69b7eff043f603bf53907c367.pdf
Normal edge-transitive Cayley graphs on the non-abelian groups of order $4p^2$, where $p$ is a prime number
Y.
Pakravesh
Department of Pure Mathematics, Faculty of Mathematical Sciences, Tarbiat Modares University P.O. Box 14115-137, Tehran, Iran.
author
Ali
Iranmanesh
Department of Pure Mathematics, Faculty of Mathematical Sciences, Tarbiat Modares University P.O. Box 14115-137, Tehran, Iran.
author
text
article
2017
eng
In this paper, we determine all of connected normal edge-transitive Cayley graphs on non-abelian groups with order $4p^2$, where $p$ is a prime number.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
3
no.
2017
951
974
http://bims.iranjournals.ir/article_1132_3af29ec84b064a55e26c93df57b943e7.pdf