Shahrood University of TechnologyJournal of Algebraic Systems2345-51286120180901MAXIMAL PRYM VARIETY AND MAXIMAL MORPHISM112125110.22044/jas.2017.6012.1301ENM.Farhadi Sangdehidepartement of math and computer science
Damghan UniversityJournal Article20170717We investigated maximal Prym varieties on finite fields by attaining their upper bounds on the number of rational points. This concept gave us a motivation for defining a generalized <br /> definition of maximal curves i.e. maximal morphisms. By MAGMA, we give some non-trivial examples of maximal morphisms that results in non-trivial examples of maximal Prym varieties.Shahrood University of TechnologyJournal of Algebraic Systems2345-51286120180901SIGNED GENERALIZED PETERSEN GRAPH AND ITS CHARACTERISTIC POLYNOMIAL1328125210.22044/jas.2017.5482.1278ENE.GhasemianDepartment of Pure Mathematics, Faculty of Mathematical Sciences, University of
Kashan, Kashan 87317-53153, I. R. Iran.Gh. H.Fath-TabarDepartment of Pure Mathematics, Faculty of Mathematical Sciences, University of
Kashan, Kashan 87317-53153, I. R. Iran.Journal Article20170304Let G^s be a signed graph, where G = (V;E) is the underlying simple graph and s : E(G) to<br /> {+, -} is the sign function on E(G). In this paper, we obtain k-th signed spectral moment and k-th signed Laplacian spectral moment of Gs together with coefﬁcients of their signed characteristic polynomial and signed Laplacian characteristic polynomial are calculated.Shahrood University of TechnologyJournal of Algebraic Systems2345-51286120180901IDEALS WITH (d1, . . . , dm)-LINEAR QUOTIENTS2942125310.22044/jas.2018.5530.1280ENL.SharifanDepartment of Mathematics and Computer Sciences, Hakim Sabzevari University,
Sabzevar, Iran
and School of Mathematics, Institute for research in Fundamental Sciences (IPM), P.O. Box: 19395-5746, Tehran, Iran.Journal Article20170317In this paper, we introduce the class of ideals with $(d_1,ldots,d_m)$-linear quotients generalizing the class of ideals with linear quotients. Under suitable conditions we control the numerical invariants of a minimal free resolution of ideals with $(d_1,ldots,d_m)$-linear quotients. In particular we show that their first module of syzygies is a componentwise linear module.Shahrood University of TechnologyJournal of Algebraic Systems2345-51286120180901<p>ON MAXIMAL IDEALS OF R<sub>∞</sub>L</p>4357125410.22044/jas.2018.6259.1311ENA. A.EstajiFaculty of Mathematics and Computer Sciences, Hakim Sabzevari University, Sabzevar, Iran.
Email: aaestaji@hsu.ac.ir and aaestaji@gmail.com0000-0001-8993-5109A.Mahmoudi DarghadamFaculty of Mathematics and Computer Sciences, Hakim Sabzevari University, Sabzevar, Iran.
Email: m.darghadam@yahoo.comJournal Article20170926Let $L$ be a completely regular frame and $mathcal{R}L$ be the ring of real-valued continuous functions<br /> on $L$.<br /> We consider the set $$mathcal{R}_{infty}L = {varphi in mathcal{R} L : uparrow varphi( dfrac{-1}{n}, dfrac{1}{n})<br /> mbox{ is a compact frame for any $n in mathbb{N}$}}.$$<br /> Suppose that $C_{infty} (X)$ is the family of all functions $f in C(X)$ for which the<br /> set ${x in X: |f(x)|geq dfrac{1}{n} }$<br /> is compact, for every $n in mathbb{N}$.<br /> Kohls has shown that $C_{infty} (X)$ is precisely the intersection<br /> of all the free maximal ideals of $C^{*}(X)$.<br /> The aim of this paper is to<br /> extend this result to<br /> the real continuous functions on a<br /> frame and hence we show that $mathcal{R}_{infty}L$ is precisely the intersection<br /> of all the free maximal ideals of $mathcal R^{*}L$.<br /> This result is used to characterize the maximal ideals in $mathcal{R}_{infty}L$.Shahrood University of TechnologyJournal of Algebraic Systems2345-51286120180901THE LATTICE OF CONGRUENCES ON A TERNARY SEMIGROUP5970125510.22044/jas.2018.5360.1273ENN.AshrafiFaculty of Mathematics, Statistics and Computer Science, Semnan University, Semnan, Iran.
Email: nashrafi@semnan.ac.irZ.YazdanmehrFaculty of Mathematics, Statistics and Computer Science, Semnan University, Semnan, Iran.
Email: zhyazdanmehr@gmail.comJournal Article20170129In this paper we investigate some properties of congruences on ternary semigroups. We also deﬁne the notion of congruence on a ternary semigroup generated by a relation and we determine the method of obtaining a congruence on a ternary semigroup T from a relation R on T. Furthermore we study the lattice of congruences on a ternary semigroup and we show that this lattice is not generally modular, it is not even semimodular. Then we indicate some conditions under which this lattice is modular.Shahrood University of TechnologyJournal of Algebraic Systems2345-51286120180901ON THE CHARACTERISTIC DEGREE OF FINITE GROUPS7180125610.22044/jas.2018.6328.1316ENZ.SepehrizadehDepartment of Pure Mathematics, Shahrekord University , P.O.Box 115, Shahrekord, Iran.
Email: zohreh.sepehri@gmail.comM. R.RismanchianDepartment of Pure Mathematics, Shahrekord University , P.O.Box 115, Shahrekord, Iran.
Email: rismanchian133@gmail.com, rismanchian@sku.ac.irJournal Article20171023In this article we introduce and study the concept of characteristic degree of a subgroup in a finite group. We define the characteristic degree of a subgroup H in a finite group G as the ratio of the number of all pairs (h,α) ∈ H×Aut(G) such that h^α∈H, by the order of H × Aut(G), where Aut(G) is the automorphisms group of G. This quantity measures the probability that H can be characteristic in G. We determine the upper and lower bounds for this probability. We also obtain a special lower bound, when H is a cyclic p-subgroup of G.