Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
6
1
2018
09
01
MAXIMAL PRYM VARIETY AND MAXIMAL MORPHISM
1
12
EN
M.
Farhadi Sangdehi
departement of math and computer science
Damghan University
farhadi@du.ac.ir
10.22044/jas.2017.6012.1301
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.
Prym Variety,Maximal Curve,Maximal Morphism
http://jas.shahroodut.ac.ir/article_1251.html
http://jas.shahroodut.ac.ir/article_1251_add36bf281698a633a65ec2e84c197b7.pdf
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
6
1
2018
09
01
SIGNED GENERALIZED PETERSEN GRAPH AND ITS CHARACTERISTIC POLYNOMIAL
13
28
EN
E.
Ghasemian
Department of Pure Mathematics, Faculty of Mathematical Sciences, University of
Kashan, Kashan 87317-53153, I. R. Iran.
e.ghasemian@yahoo.com
Gh. H.
Fath-Tabar
Department of Pure Mathematics, Faculty of Mathematical Sciences, University of
Kashan, Kashan 87317-53153, I. R. Iran.
fathtabar@kashanu.ac.ir
10.22044/jas.2017.5482.1278
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.
Singed graph,Signed Petersen graph,Adjacency matrix,Signed Laplacian matrix
http://jas.shahroodut.ac.ir/article_1252.html
http://jas.shahroodut.ac.ir/article_1252_1cac8794e05806be8ceb9da24ee63f0a.pdf
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
6
1
2018
09
01
IDEALS WITH (d1, . . . , dm)-LINEAR QUOTIENTS
29
42
EN
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.
leilasharifan@gmail.com
10.22044/jas.2018.5530.1280
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.
Mapping cone,componentwise linear module,regularity
http://jas.shahroodut.ac.ir/article_1253.html
http://jas.shahroodut.ac.ir/article_1253_5095867677dfc53231fca042ab87af79.pdf
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
6
1
2018
09
01
ON MAXIMAL IDEALS OF R∞L
43
57
EN
A. A.
Estaji
Faculty of Mathematics and Computer Sciences, Hakim Sabzevari University, Sabzevar, Iran.
Email: aaestaji@hsu.ac.ir and aaestaji@gmail.com
aaestaji@gmail.com
A.
Mahmoudi Darghadam
Faculty of Mathematics and Computer Sciences, Hakim Sabzevari University, Sabzevar, Iran.
Email: m.darghadam@yahoo.com
m.darghadam@yahoo.com
10.22044/jas.2018.6259.1311
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 $mathcal{R}_{infty}L$.
Frame,Compact,Maximal ideal,Ring of real valued continuous functions
http://jas.shahroodut.ac.ir/article_1254.html
http://jas.shahroodut.ac.ir/article_1254_b7ff14694dc7c2f170a0a9a6677d196b.pdf
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
6
1
2018
09
01
THE LATTICE OF CONGRUENCES ON A TERNARY SEMIGROUP
59
70
EN
N.
Ashrafi
Faculty of Mathematics, Statistics and Computer Science, Semnan University, Semnan, Iran.
Email: nashrafi@semnan.ac.ir
nashrafi@semnan.ac.ir
Z.
Yazdanmehr
Faculty of Mathematics, Statistics and Computer Science, Semnan University, Semnan, Iran.
Email: zhyazdanmehr@gmail.com
zhyazdanmehr@gmail.com
10.22044/jas.2018.5360.1273
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.
Ternary semigroup,congruence,lattice
http://jas.shahroodut.ac.ir/article_1255.html
http://jas.shahroodut.ac.ir/article_1255_8c225bd8fff71b0f902c27667ee224cb.pdf
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
6
1
2018
09
01
ON THE CHARACTERISTIC DEGREE OF FINITE GROUPS
71
80
EN
Z.
Sepehrizadeh
Department of Pure Mathematics, Shahrekord University , P.O.Box 115, Shahrekord, Iran.
Email: zohreh.sepehri@gmail.com
zohreh.sepehri@gmail.com
M. R.
Rismanchian
Department of Pure Mathematics, Shahrekord University , P.O.Box 115, Shahrekord, Iran.
Email: rismanchian133@gmail.com, rismanchian@sku.ac.ir
rismanchian133@gmail.com
10.22044/jas.2018.6328.1316
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.
Autocommutativity degree,Characteristic degree,p-group
http://jas.shahroodut.ac.ir/article_1256.html
http://jas.shahroodut.ac.ir/article_1256_dc3a82544bbbd50166de79daec83f997.pdf