MAXIMAL PRYM VARIETY AND MAXIMAL MORPHISM
M.
Farhadi Sangdehi
departement of math and computer science
Damghan University
author
text
article
2018
eng
We 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 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.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
6
v.
1
no.
2018
1
12
http://jas.shahroodut.ac.ir/article_1251_754f567f47608f98c2a43186b7dde0ee.pdf
dx.doi.org/10.22044/jas.2017.6012.1301
SIGNED GENERALIZED PETERSEN GRAPH AND ITS CHARACTERISTIC POLYNOMIAL
E.
Ghasemian
Department of Pure Mathematics, Faculty of Mathematical Sciences, University of
Kashan, Kashan 87317-53153, I. R. Iran.
author
Gh. H.
Fath-Tabar
Department of Pure Mathematics, Faculty of Mathematical Sciences, University of
Kashan, Kashan 87317-53153, I. R. Iran.
author
text
article
2018
eng
Let G^s be a signed graph, where G = (V;E) is the underlying simple graph and s : E(G) to {+, -} 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.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
6
v.
1
no.
2018
13
28
http://jas.shahroodut.ac.ir/article_1252_6c32e6bd4ccfe3ab6aa2450e8fa4c181.pdf
dx.doi.org/10.22044/jas.2017.5482.1278
IDEALS WITH (d1, . . . , dm)-LINEAR QUOTIENTS
L.
Sharifan
Department 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.
author
text
article
2018
eng
In 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.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
6
v.
1
no.
2018
29
42
http://jas.shahroodut.ac.ir/article_1253_6f8ef72f643795159174715408d317ee.pdf
dx.doi.org/10.22044/jas.2018.5530.1280
ON MAXIMAL IDEALS OF R∞L
A. A.
Estaji
Faculty of Mathematics and Computer Sciences, Hakim Sabzevari University, Sabzevar, Iran.
Email: aaestaji@hsu.ac.ir and aaestaji@gmail.com
author
A.
Mahmoudi Darghadam
Faculty of Mathematics and Computer Sciences, Hakim Sabzevari University, Sabzevar, Iran.
Email: m.darghadam@yahoo.com
author
text
article
2018
eng
Let $L$ be a completely regular frame and $\mathcal{R}L$ be the ring of real-valued continuous functions on $L$. We consider the set $$\mathcal{R}_{\infty}L = \{\varphi \in \mathcal{R} L : \uparrow \varphi( \dfrac{-1}{n}, \dfrac{1}{n}) \mbox{ is a compact frame for any $n \in \mathbb{N}$}\}.$$ Suppose that $C_{\infty} (X)$ is the family of all functions $f \in C(X)$ for which the set $\{x \in X: |f(x)|\geq \dfrac{1}{n} \}$ is compact, for every $n \in \mathbb{N}$. Kohls has shown that $C_{\infty} (X)$ is precisely the intersection of all the free maximal ideals of $C^{*}(X)$. The aim of this paper is to extend this result to the real continuous functions on a frame and hence we show that $\mathcal{R}_{\infty}L$ is precisely the intersection of all the free maximal ideals of $\mathcal R^{*}L$. This result is used to characterize the maximal ideals in $\mathcal{R}_{\infty}L$.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
6
v.
1
no.
2018
43
57
http://jas.shahroodut.ac.ir/article_1254_45a4703f3fc3297b882c27efeed5d7db.pdf
dx.doi.org/10.22044/jas.2018.6259.1311
THE LATTICE OF CONGRUENCES ON A TERNARY SEMIGROUP
N.
Ashrafi
Faculty of Mathematics, Statistics and Computer Science, Semnan University, Semnan, Iran.
Email: nashrafi@semnan.ac.ir
author
Z.
Yazdanmehr
Faculty of Mathematics, Statistics and Computer Science, Semnan University, Semnan, Iran.
Email: zhyazdanmehr@gmail.com
author
text
article
2018
eng
In 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.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
6
v.
1
no.
2018
59
70
http://jas.shahroodut.ac.ir/article_1255_585b8d0ca4e05982b434b1a9d2ab912e.pdf
dx.doi.org/10.22044/jas.2018.5360.1273
ON THE CHARACTERISTIC DEGREE OF FINITE GROUPS
Z.
Sepehrizadeh
Department of Pure Mathematics, Shahrekord University , P.O.Box 115, Shahrekord, Iran.
Email: zohreh.sepehri@gmail.com
author
M. R.
Rismanchian
Department of Pure Mathematics, Shahrekord University , P.O.Box 115, Shahrekord, Iran.
Email: rismanchian133@gmail.com, rismanchian@sku.ac.ir
author
text
article
2018
eng
In 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.
Journal of Algebraic Systems
Shahrood University of Technology
2345-5128
6
v.
1
no.
2018
71
80
http://jas.shahroodut.ac.ir/article_1256_9cb3d15cf6327aa4481ad9fb54223403.pdf
dx.doi.org/10.22044/jas.2018.6328.1316