ORIGINAL_ARTICLE
A COVERING PROPERTY IN PRINCIPAL BUNDLES
Let $p:X\lo B$ be a locally trivial principal G-bundle and $\wt{p}:\wt{X}\lo B$ be a locally trivial principal $\wt{G}$-bundle. In this paper, by using the structure of principal bundles according to transition functions, we show that $\wt{G}$ is a covering group of $G$ if and only if $\wt{X}$ is a covering space of $X$. Then we conclude that a topological space $X$ with non-simply connected universal covering space has no connected locally trivial principal $\pi(X,x_0)$-bundle, for every $x_0\in X$.
http://jas.shahroodut.ac.ir/article_1093_2fa7e7be0e8cdd89821d84d3247cd729.pdf
2018-01-01T11:23:20
2019-01-20T11:23:20
91
98
10.22044/jas.2018.1093
Principal bundle
covering space
covering group
A.
Pakdaman
a.pakdaman@gu.ac.ir
true
1
Department of Mathematics, University of Golestan, P.O.Box 155, Gorgan, Iran.
Department of Mathematics, University of Golestan, P.O.Box 155, Gorgan, Iran.
Department of Mathematics, University of Golestan, P.O.Box 155, Gorgan, Iran.
LEAD_AUTHOR
M.
Attary
m_atari1989@yahoo.com
true
2
Department of Mathematics, University of Golestan, P.O.Box 155, Gorgan, Iran.
Department of Mathematics, University of Golestan, P.O.Box 155, Gorgan, Iran.
Department of Mathematics, University of Golestan, P.O.Box 155, Gorgan, Iran.
AUTHOR
ORIGINAL_ARTICLE
ON (n -1; n)-phi-m-PRIME AND (n -1; n)-WEAKLY PRIME SUBMODULES
Abstract. Let m; n ≥ 2 be two positive integers, R a commutative ring with identity and M a unitary R-module. A proper submodule P of M is an (n 1; n)-Φm-prime ((n 1; n)-weakly prime) submodule if a1; : : : ; an1 2 R and x 2 M together with a1 : : : an1x 2 Pn(P : M)m1P (0 ̸= a1 : : : an1x 2 P) imply a1 : : : ai1ai+1 : : : an1x 2 P, for some i 2 f1; : : : ; n1g or a1:::an1 2 (P : M). In this paper we study these submodules. Some useful results and examples concerning these types of submodules are given.
http://jas.shahroodut.ac.ir/article_1094_062414660840fa42c0c0d4ea6447a7ca.pdf
2018-01-01T11:23:20
2019-01-20T11:23:20
99
109
10.22044/jas.2017.4332.1217
Quasi-local ring, Weakly prime submodule, (n-1
n)-weakly prime submodule, ϕm-prime submodule
M.
Ebrahimpour
m.ebrahimpour@vru.ac.ir
true
1
Department of Mathematics, Faculty of Sciences, Vali-e-Asr University of Rafsanjan
, P.O.Box 518, Rafsanjan, Iran
Department of Mathematics, Faculty of Sciences, Vali-e-Asr University of Rafsanjan
, P.O.Box 518, Rafsanjan, Iran
Department of Mathematics, Faculty of Sciences, Vali-e-Asr University of Rafsanjan
, P.O.Box 518, Rafsanjan, Iran
LEAD_AUTHOR
F.
Mirzaee
mirzaee0269@yahoo.com
true
2
Department of Mathematics, Faculty of Sciences, Shahid Bahonar University of
Kerman, Kerman, Iran.
Department of Mathematics, Faculty of Sciences, Shahid Bahonar University of
Kerman, Kerman, Iran.
Department of Mathematics, Faculty of Sciences, Shahid Bahonar University of
Kerman, Kerman, Iran.
AUTHOR
ORIGINAL_ARTICLE
SEQUENTIALLY COMPACT S-ACTS
The investigation of equational compactness was initiated by Banaschewski and Nelson. They proved that pure injectivity is equivalent to equational compactness. Here we define the so called sequentially compact acts over semigroups and study some of their categorical and homological properties. Some Baer conditions for injectivity of S-acts are also presented.
http://jas.shahroodut.ac.ir/article_1095_09001f39c3743b6d98c90f11286807eb.pdf
2018-01-01T11:23:20
2019-01-20T11:23:20
111
125
10.22044/jas.2017.4357.1218
sequentially compact
$f$-pure injective
injective S-act
H.
Barzegar
h56bar@tafreshu.ac.ir
true
1
Department of Mathematics, University of Tafresh , 3951879611, Tafresh, Iran.
Department of Mathematics, University of Tafresh , 3951879611, Tafresh, Iran.
Department of Mathematics, University of Tafresh , 3951879611, Tafresh, Iran.
LEAD_AUTHOR
ORIGINAL_ARTICLE
TOTAL DOMINATION POLYNOMIAL OF GRAPHS FROM PRIMARY SUBGRAPHS
Let $G = (V, E)$ be a simple graph of order $n$. The total dominating set is a subset $D$ of $V$ that every vertex of $V$ is adjacent to some vertices of $D$. The total domination number of $G$ is equal to minimum cardinality of total dominating set in $G$ and denoted by $\gamma_t(G)$. The total domination polynomial of $G$ is the polynomial $D_t(G,x)=\sum d_t(G,i)$, where $d_t(G,i)$ is the number of total dominating sets of $G$ of size $i$. Let $G$ be a connected graph constructed from pairwise disjoint connected graphs $G_1,\ldots ,G_k$ by selecting a vertex of $G_1$, a vertex of $G_2$, and identify these two vertices. Then continue in this manner inductively. We say that $G$ is obtained by point-attaching from $G_1, \ldots ,G_k$ and that $G_i$'s are the primary subgraphs of $G$. In this paper, we consider some particular cases of these graphs that most of them are of importance in chemistry and study their total domination polynomials.
http://jas.shahroodut.ac.ir/article_1096_6bc97a7ad506ba2ec801a8f784bf5401.pdf
2018-01-01T11:23:20
2019-01-20T11:23:20
127
138
10.22044/jas.2018.1096
Total domination number
total domination polynomial
total dominating set
S.
Alikhani
alikhani@yazd.ac.ir
true
1
Department of Mathematics, Yazd University, 89195-741, Yazd, Iran.
Department of Mathematics, Yazd University, 89195-741, Yazd, Iran.
Department of Mathematics, Yazd University, 89195-741, Yazd, Iran.
LEAD_AUTHOR
N.
Jafari
nasrin7190@yahoo.com
true
2
Department of Mathematics, Yazd University, 89195-741 Yazd, Iran.
Department of Mathematics, Yazd University, 89195-741 Yazd, Iran.
Department of Mathematics, Yazd University, 89195-741 Yazd, Iran.
AUTHOR
ORIGINAL_ARTICLE
ON p-NILPOTENCY OF FINITE GROUPS WITH SS-NORMAL SUBGROUPS
Abstract. A subgroup H of a group G is said to be SS-embeddedin G if there exists a normal subgroup T of G such that HT issubnormal in G and H \ T ≤ H sG , where H sG is the maximal s-permutable subgroup of G contained in H. We say that a subgroupH is an SS-normal subgroup in G if there exists a normal subgroupT of G such that G = HT and H \ T ≤ H SS , where H SS is anSS-embedded subgroup of G contained in H. In this paper, westudy the inﬂuence of some SS-normal subgroups on the structureof a ﬁnite group G.
http://jas.shahroodut.ac.ir/article_1097_93130e6e1cee6308e51da0e234136680.pdf
2018-01-01T11:23:20
2019-01-20T11:23:20
139
148
10.22044/jas.2017.5274.1270
SS-normal subgroup
SS-embedded subgroup
p-nilpotent group
G. R.
REZAEEZADEH
gh.rezaeezadeh@yahoo.com
true
1
Department of Mathematics, University of Shahrekord, P.O.Box 115, Shahrekord,
Iran.
Department of Mathematics, University of Shahrekord, P.O.Box 115, Shahrekord,
Iran.
Department of Mathematics, University of Shahrekord, P.O.Box 115, Shahrekord,
Iran.
LEAD_AUTHOR
Z.
AGHAJARI
z.aghajari@stu.sku.ac.ir
true
2
Department of Mathematics, University of Shahrekord, P.O.Box 115, Shahrekord,
Iran.
Department of Mathematics, University of Shahrekord, P.O.Box 115, Shahrekord,
Iran.
Department of Mathematics, University of Shahrekord, P.O.Box 115, Shahrekord,
Iran.
AUTHOR
ORIGINAL_ARTICLE
INTERSECTION OF ESSENTIAL IDEALS IN THE RING OF REAL-VALUED CONTINUOUS FUNCTIONS ON A FRAME
A frame $L$ is called {\it coz-dense} if $\Sigma_{coz(\alpha)}=\emptyset$ implies $\alpha=\mathbf 0$. Let $\mathcal RL$ be the ring of real-valued continuous functions on a coz-dense and completely regular frame $L$. We present a description of the socle of the ring $\mathcal RL$ based on minimal ideals of $\mathcal RL$ and zero sets in pointfree topology. We show that socle of $\mathcal RL$ is an essential ideal in $\mathcal RL$ if and only if the set of isolated points of $ \Sigma L$ is dense in $ \Sigma L$ if and only if the intersection of any family of essential ideals is essential in $\mathcal RL$. Besides, the counterpart of some results in the ring $C(X)$ is studied for the ring $\mathcal RL$. For example, an ideal $E$ of $\mathcal RL$ is an essential ideal if and only if $\bigcap Z[E]$ is a nowhere dense subset of $\Sigma L.$
http://jas.shahroodut.ac.ir/article_1099_9dfc8c0b4509368b035dd36aa8a9f7c3.pdf
2018-01-01T11:23:20
2019-01-20T11:23:20
149
161
10.22044/jas.2017.5302.1272
Frame
essential ideal
socle
zero sets in pointfree topology
ring of real-valued continuous functions on a frame
A. A.
Estaji
aaestaji@hsu.ac.ir
true
1
Faculty of Mathematics and Computer Sciences, Hakim Sabzevari University, Sabze-
var, Iran.
Faculty of Mathematics and Computer Sciences, Hakim Sabzevari University, Sabze-
var, Iran.
Faculty of Mathematics and Computer Sciences, Hakim Sabzevari University, Sabze-
var, Iran.
AUTHOR
A. Gh.
Karimi Feizabadi
akarimi@gorganiau.ac.ir
true
2
Department of Mathematics, Gorgan Branch, Islamic Azad University, Gorgan,
Department of Mathematics, Gorgan Branch, Islamic Azad University, Gorgan,
Department of Mathematics, Gorgan Branch, Islamic Azad University, Gorgan,
AUTHOR
M.
Abedi
abedi@esfarayen.ac.ir
true
3
Esfarayen University of Technology, Esfarayen, Iran.
Esfarayen University of Technology, Esfarayen, Iran.
Esfarayen University of Technology, Esfarayen, Iran.
LEAD_AUTHOR
ORIGINAL_ARTICLE
A GENERALIZATION OF CORETRACTABLE MODULES
Let $R$ be a ring and $M$ a right $R$-module. We call $M$, coretractable relative to $\overline{Z}(M)$ (for short, $\overline{Z}(M)$-coretractable) provided that, for every proper submodule $N$ of $M$ containing $\overline{Z}(M)$, there is a nonzero homomorphism $f:\dfrac{M}{N}\rightarrow M$. We investigate some conditions under which the two concepts coretractable and $\overline{Z}(M)$-coretractable, coincide. For a commutative semiperfect ring $R$, we show that $R$ is $\overline{Z}(R)$-coretractable if and only if $R$ is a Kasch ring. Some examples are provided to illustrate different concepts.
http://jas.shahroodut.ac.ir/article_1100_af402bec4a5048425b463558a46102a6.pdf
2018-01-01T11:23:20
2019-01-20T11:23:20
163
176
10.22044/jas.2017.5736.1287
coretractable module
$overline{Z}(M)$-coretractable module
Kasch ring
A. R.
Moniri Hamzekolaee
a.monirih@umz.ac.ir
true
1
Department of Mathematics, University of Mazandaran, Babolsar, Iran
Department of Mathematics, University of Mazandaran, Babolsar, Iran
Department of Mathematics, University of Mazandaran, Babolsar, Iran
LEAD_AUTHOR