University of Mazandaran
Caspian Journal of Mathematical Sciences (CJMS)
1735-0611
6
1
2017
01
01
Warped product and quasi-Einstein metrics
1
8
EN
Buddhadev
Pal
University of Calcutta
pal.buddha@gmail.com
Arindam
Bhattacharyya
Jadavpur University
bhattachar1968@yahoo.co.in
Santu
Dey
Jadavpur University
santu.mathju@gmail.com
10.22080/cjms.2017.1635
Warped products provide a rich class of physically significant geometric objects. Warped product construction is an important method to produce a new metric with a base manifold and a fibre. We construct compact base manifolds with a positive scalar curvature which do not admit any non-trivial quasi-Einstein warped product, and non compact complete base manifolds which do not admit any non-trivial Ricci-flat quasi-Einstein warped product
warped product,quasi-Einstein space,compact base manifolds
http://cjms.journals.umz.ac.ir/article_1635.html
http://cjms.journals.umz.ac.ir/article_1635_cb0159ef48f22f008d96a7c16c50d1f2.pdf
University of Mazandaran
Caspian Journal of Mathematical Sciences (CJMS)
1735-0611
6
1
2017
01
01
Reduction of Differential Equations by Lie Algebra of Symmetries
9
30
EN
S. Reza
Hejazi
Department of Mathematics, University of Shahrood, Shahrood, Semnan, Iran.
ra.hejazi@gmail.com
10.22080/cjms.2017.1636
The paper is devoted to an application of Lie group theory to differential equations. The basic infinitesimal method for calculating symmetry group is presented, and used to determine general symmetry group of some differential equations. We include a number of important applications including integration of ordinary differential equations and finding some solutions of partial differential equations together with some examples. A Bianchi theorem for the solvable symmetry groups is given to reduce a system of ordinary differential equations.
Symmetry,Lie Group,Invariance
http://cjms.journals.umz.ac.ir/article_1636.html
http://cjms.journals.umz.ac.ir/article_1636_cb984d580c423c494eedb52c01845388.pdf
University of Mazandaran
Caspian Journal of Mathematical Sciences (CJMS)
1735-0611
6
1
2017
01
01
Characterizations of Slant Ruled Surfaces in the Euclidean 3-space
31
46
EN
Mehmet
Önder
0000-0002-9354-5530
Delibekirli Village
mehmetonder197999@gmail.com
Onur
Kaya
Manisa Celal Bayar University
onur.kaya@cbu.edu.tr
10.22080/cjms.2017.1637
In this study, we give the relationships between the conical curvatures of ruled surfaces generated by the unit vectors of the ruling, central normal and central tangent of a ruled surface in the Euclidean 3-space E^3. We obtain differential equations characterizing slant ruled surfaces and if the reference ruled surface is a slant ruled surface, we give the conditions for the surfaces generated by central normal and central tangent vectors to be slant ruled surfaces.
Slant ruled surface,Frenet frame,Conical curvature,Differential equation
http://cjms.journals.umz.ac.ir/article_1637.html
http://cjms.journals.umz.ac.ir/article_1637_3dfbcc7f597530eed764d94b1e14a96f.pdf
University of Mazandaran
Caspian Journal of Mathematical Sciences (CJMS)
1735-0611
6
1
2017
01
01
On the determination of eigenvalues for differential pencils with the turning point
47
53
EN
A.
Neamaty
University of Mazandaran
neamaty7@gmail.com
Y.
Khalili
Department of Basic Sciences, Sari
Agricultural Sciences and Natural Resources University, Sari, Iran
10.22080/cjms.2017.1644
In this paper, we investigatethe boundary value problem for differential pencils on the half-linewith a turning point. Using a fundamental system of solutions, wegive a asymptotic distribution of eigenvalues.
Eigenvalues,Differential pencil,Turning point
http://cjms.journals.umz.ac.ir/article_1644.html
http://cjms.journals.umz.ac.ir/article_1644_cccdcc4d07e2d9aa5a28063a8e403ecf.pdf
University of Mazandaran
Caspian Journal of Mathematical Sciences (CJMS)
1735-0611
6
1
2017
01
01
A local approach to the entropy of countable fuzzy partitions
54
61
EN
R.
R. Ghasemkhani
Department of Mathematics, Faculty of Science
University of Jiroft, Jiroft, Iran. 78671-61167
u.
Mohammadi
Department of Mathematics, Faculty of Science
University of Jiroft, Jiroft, Iran. 78671-61167
u.mohamadi@ujiroft.ac.ir
10.22080/cjms.2017.1646
This paper denes and investigates the ergodic proper-ties of the entropy of a countable partition of a fuzzy dynamical sys-tem at different points of the state space. It ultimately introducesthe local fuzzy entropy of a fuzzy dynamical system and proves itto be an isomorphism invariant.
Local entropy,countable partition,local diameter
http://cjms.journals.umz.ac.ir/article_1646.html
http://cjms.journals.umz.ac.ir/article_1646_b05fc6a1751fa4d5ce50e2c2e41b8460.pdf