2018-06-19T07:34:46Z
http://cjms.journals.umz.ac.ir/?_action=export&rf=summon&issue=304
Caspian Journal of Mathematical Sciences (CJMS)
CJMS
1735-0611
1735-0611
2017
6
1
Warped product and quasi-Einstein metrics
Buddhadev
Pal
Arindam
Bhattacharyya
Santu
Dey
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
2017
01
01
1
8
http://cjms.journals.umz.ac.ir/article_1635_cb0159ef48f22f008d96a7c16c50d1f2.pdf
Caspian Journal of Mathematical Sciences (CJMS)
CJMS
1735-0611
1735-0611
2017
6
1
Reduction of Differential Equations by Lie Algebra of Symmetries
S. Reza
Hejazi
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
2017
01
01
9
30
http://cjms.journals.umz.ac.ir/article_1636_cb984d580c423c494eedb52c01845388.pdf
Caspian Journal of Mathematical Sciences (CJMS)
CJMS
1735-0611
1735-0611
2017
6
1
Characterizations of Slant Ruled Surfaces in the Euclidean 3-space
Mehmet
Önder
Onur
Kaya
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
2017
01
01
31
46
http://cjms.journals.umz.ac.ir/article_1637_3dfbcc7f597530eed764d94b1e14a96f.pdf
Caspian Journal of Mathematical Sciences (CJMS)
CJMS
1735-0611
1735-0611
2017
6
1
On the determination of eigenvalues for differential pencils with the turning point
A.
Neamaty
Y.
Khalili
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
2017
01
01
47
53
http://cjms.journals.umz.ac.ir/article_1644_cccdcc4d07e2d9aa5a28063a8e403ecf.pdf
Caspian Journal of Mathematical Sciences (CJMS)
CJMS
1735-0611
1735-0611
2017
6
1
A local approach to the entropy of countable fuzzy partitions
R.
R. Ghasemkhani
u.
Mohammadi
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
2017
01
01
54
61
http://cjms.journals.umz.ac.ir/article_1646_b05fc6a1751fa4d5ce50e2c2e41b8460.pdf