AMENABILITY OF VECTOR VALUED GROUP ALGEBRAS
Ali
Ghaffari
Department of Mathematics, Semnan University, Semnan, Iran
author
Seyedeh Samaneh
Javadi Syahkale
Faculty of Engineering- East Guilan, University of Guilan, Rudsar, Iran
author
text
article
2015
eng
The purpose of this article is to develop the notions of amenabilityfor vector valued group algebras. We prove that L1(G, A) is approximatelyweakly amenable where A is a unital separable Banach algebra. We givenecessary and sufficient conditions for the existence of a left invariant meanon L∞(G, A∗), LUC(G, A∗), WAP(G, A∗) and C0(G, A∗).
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
3
v.
2
no.
2015
97
107
http://jas.shahroodut.ac.ir/article_610_80140794b33ad022f3303e700e885240.pdf
dx.doi.org/10.22044/jas.2015.610
IDEALS IN EL-SEMIHYPERGROUPS ASSOCIATED TO ORDERED SEMIGROUPS
S. H.
Ghazavi
Department of Mathematics-Yazd University-Yazd-Iran
author
S. M.
Anvariyeh
Department Of Mathematics-Yazd University-Yazd-Iran
author
S.
Mirvakili
Department of Mathematics, Payame Noor University, Tehran, Iran
author
text
article
2015
eng
In this paper, we attempt to investigate the connection between various types of ideals (for examples $(m, n)$-ideal, bi-ideal, interior ideal, quasi ideal, prime ideal and maximal ideal) of an ordered semigroup $(S,cdot ,leq)$ and the correspond hyperideals of its EL-hyperstructure $(S,*)$ (if exists). Moreover, we construct the class of EL-$Gamma$-semihypergroup associated to a partially ordered $Gamma$-semigroup.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
3
v.
2
no.
2015
109
125
http://jas.shahroodut.ac.ir/article_611_edab4a829eab96599e8b252cfea28168.pdf
dx.doi.org/10.22044/jas.2015.611
ON ABSOLUTE CENTRAL AUTOMORPHISMS FIXING THE CENTER ELEMENTWISE
Zahra
Kaboutari Farimani
Department of Mathematics, University of Birjand, Birjand, Iran.
author
Mohammad Mehdi
Nasrabadi
Department of Mathematics, University of Birjand, Birjand, Iran.
author
text
article
2015
eng
Let G be a finite p-group and let Aut_l(G) be the group of absolute central automorphisms of G. In this paper we give necessary and sufficient condition on G such that each absolute central automorphism of G fixes the centre element-wise. Also we classify all groups of orders p^3 and p^4 whose absolute central automorphisms fix the centre element-wise.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
3
v.
2
no.
2015
127
131
http://jas.shahroodut.ac.ir/article_612_1811e3d5e5fb09d4b5f4e6ce4fb36612.pdf
dx.doi.org/10.22044/jas.2015.612
ON GRADED LOCAL COHOMOLOGY MODULES DEFINED BY A PAIR OF IDEALS
Maryam
Jahangiri
Faculty of Mathematical Sciences and Computer, Kharazmi University, Tehran,
Iran AND Institute for Research in Fundamental Sciences (IPM) P.O.Box: 19395-
5746, Tehran, Iran.
author
Zohreh
Habibbi
Department of Mathematics, University of Payame Noor, P.O.Box 19395-3697,
Tehran, Iran.
author
text
article
2015
eng
Let $R = bigoplus_{n in mathbb{N}_{0}} R_{n}$ be a standardgraded ring, $M$ be a finitely generated graded $R$-module and $J$be a homogenous ideal of $R$. In this paper we study the gradedstructure of the $i$-th local cohomology module of $M$ defined by apair of ideals $(R_{+},J)$, i.e. $H^{i}_{R_{+},J}(M)$. Moreprecisely, we discuss finiteness property and vanishing of thegraded components $H^{i}_{R_{+},J}(M)_{n}$.Also, we study the Artinian property and tameness of certainsubmodules and quotient modules of $H^{i}_{R_{+},J}(M)$.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
3
v.
2
no.
2015
133
146
http://jas.shahroodut.ac.ir/article_613_c40acc726617eb0a6a9ca9a12b7a2e55.pdf
dx.doi.org/10.22044/jas.2015.613
RESULTS ON ALMOST COHEN-MACAULAY MODULES
A.
Mafi
Department of Mathematics, University of Kurdistan, P.O.Box 416, Sanandaj,
Iran.
author
S.
Tabejamaat
Department of Mathematics, Payame Noor University, P.O.Box 19395-3697,
Tehran, Iran.
author
text
article
2015
eng
Let $(R,\underline{m})$ be a commutative Noetherian local ring and $M$ be a non-zero finitely generated $R$-module. We show that if $R$ is almost Cohen-Macaulay and $M$ is perfect with finite projective dimension, then $M$ is an almost Cohen-Macaulay module. Also, we give some necessary and sufficient condition on $M$ to be an almost Cohen-Macaulay module, by using $\Ext$ functors.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
3
v.
2
no.
2015
147
150
http://jas.shahroodut.ac.ir/article_614_d7afaf2c070483f534a968021ba416ea.pdf
dx.doi.org/10.22044/jas.2015.614
RATIONAL CHARACTER TABLE OF SOME FINITE GROUPS
H.
Shabani
Department of Pure Mathematics, Faculty of Mathematical Sciences, University of
Kashan, Kashan 87317−51167, I. R. Iran.
author
A. R.
Ashrafi
Department of Pure Mathematics, Faculty of Mathematical Sciences, University of
Kashan, Kashan 87317−51167, I. R. Iran.
author
M.
Ghorbani
Department of Mathematics, Faculty of Science, Shahid Rajaee Teacher Training
University, Tehran, 16785 - 136, I. R. Iran.
author
text
article
2015
eng
The aim of this paper is to compute the rational character tables of the dicyclic group $T_{4n}$, the groups of order $pq$ and $pqr$. Some general properties of rational character tables are also considered into account.The aim of this paper is to compute the rational character tables of the dicyclic group $T_{4n}$, the groups of order $pq$ and $pqr$. Some general properties of rational character tables are also considered into account.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
3
v.
2
no.
2015
151
169
http://jas.shahroodut.ac.ir/article_615_def3b04d2ccfdc9937fb673747390703.pdf
dx.doi.org/10.22044/jas.2015.615
MAGMA-JOINED-MAGMAS: A CLASS OF NEW ALGEBRAIC STRUCTURES
M. H.
Hooshmand
Young Researchers and Elite Club, Shiraz Branch, Islamic Azad University, Shiraz,
Iran.
author
text
article
2015
eng
By left magma-$e$-magma, I mean a set containingthe fixed element $e$, and equipped by two binary operations "$cdot$", $odot$ with the property $eodot (xcdot y)=eodot(xodot y)$, namelyleft $e$-join law. So, $(X,cdot,e,odot)$ is a left magma-$e$-magmaif and only if $(X,cdot)$, $(X,odot)$ are magmas (groupoids), $ein X$ and the left $e$-join law holds.Right (and two-sided) magma-$e$-magmas are defined in an analogous way.Also, $X$ is magma-joined-magma if it is magma-$x$-magma, for all $xin X$. Therefore, we introduce a big class of basicalgebraic structures with two binary operations which some of theirsub-classes are group-$e$-semigroups, loop-$e$-semigroups, semigroup-$e$-quasigroups,etc. A nice infinite [resp. finite] example for them is real group-grouplike $(mathbb{R},+,0,+_1)$ [resp. Klein group-grouplike].In this paper, I introduce and study the topic, construct several big classes of such algebraic structures and characterizeall identical magma-$e$-magma in several ways. The motivation of this study lies in some interesting connections to $f$-Multiplications, some basic functional equations on algebraic structures and Grouplikes (recently been introduced by the author). At last, we show some of future directionsfor the researches.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
3
v.
2
no.
2015
171
199
http://jas.shahroodut.ac.ir/article_616_129e9f74cb580b363d2f9eb90a41a37f.pdf
dx.doi.org/10.22044/jas.2015.616
NONNIL-NOETHERIAN MODULES OVER COMMUTATIVE RINGS
A.
Yousefian Darani
Department of Mathematics and Applications, University of Mohaghegh Ardabili,
P.O.Box 5619911367, Ardabil, Iran.
author
text
article
2015
eng
In this paper we introduce a new class of modules which is closely related to the class of Noetherian modules. Let $R$ be a commutative ring with identity and let $M$ be an $R$-module such that $Nil(M)$ is a divided prime submodule of $M$. $M$ is called a Nonnil-Noetherian $R$-module if every nonnil submodule of $M$ is finitely generated. We prove that many of the properties of Noetherian modules are also true for Nonnil-Noetherian modules.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
3
v.
2
no.
2015
201
210
http://jas.shahroodut.ac.ir/article_618_ab7aebe1bfa094cd9b11cca2200588f0.pdf
dx.doi.org/10.22044/jas.2015.618
A SHORT PROOF OF A RESULT OF NAGEL
N.
Shirmohammadi
Department of Mathematics, University of Tabriz, P.O.Box 51666-16471, Tabriz,
Iran.
author
text
article
2015
eng
Let $(R,fm)$ be a Gorenstein local ring and$M,N$ be two finitely generated modules over $R$. Nagel proved that if $M$ and $N$ are inthe same even liaison class, thenone has $H^i_{fm}(M)cong H^i_{fm}(N)$ for all $iIn this paper, we provide a short proof to this result.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
3
v.
2
no.
2015
211
215
http://jas.shahroodut.ac.ir/article_619_3984f444570261f2e3b6227586b24b67.pdf
dx.doi.org/10.22044/jas.2015.619
ON THE VANISHING OF DERIVED LOCAL HOMOLOGY MODULES
M.
Hatamkhani
Department of Mathematics,
Faculty of Science,
Arak University,
Arak, 38156-8-8349, Iran.
author
text
article
2015
eng
Let $R$ be a commutative Noetherian ring, $fa$ anideal of $R$ and $mathcal{D}(R)$ denote the derived category of$R$-modules. For any homologically bounded complex $X$, we conjecture that$sup {bf L}Lambda^{fa}(X)leq$ mag$_RX$. We prove thisin several cases. This generalize the main result of Hatamkhani and Divaani-Aazar cite{HD} for complexes.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
3
v.
2
no.
2015
217
225
http://jas.shahroodut.ac.ir/article_620_374b709d91ba6ee24f3f79fde8febcf8.pdf
dx.doi.org/10.22044/jas.2015.620