Warped product and quasi-Einstein metrics
Buddhadev
Pal
University of Calcutta
author
Arindam
Bhattacharyya
Jadavpur University
author
Santu
Dey
Jadavpur University
author
text
article
2017
eng
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
Caspian Journal of Mathematical Sciences (CJMS)
University of Mazandaran
1735-0611
6
v.
1
no.
2017
1
8
http://cjms.journals.umz.ac.ir/article_1635_cb0159ef48f22f008d96a7c16c50d1f2.pdf
dx.doi.org/10.22080/cjms.2017.1635
Reduction of Differential Equations by Lie Algebra of Symmetries
S. Reza
Hejazi
Department of Mathematics, University of Shahrood, Shahrood, Semnan, Iran.
author
text
article
2017
eng
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.
Caspian Journal of Mathematical Sciences (CJMS)
University of Mazandaran
1735-0611
6
v.
1
no.
2017
9
30
http://cjms.journals.umz.ac.ir/article_1636_cb984d580c423c494eedb52c01845388.pdf
dx.doi.org/10.22080/cjms.2017.1636
Characterizations of Slant Ruled Surfaces in the Euclidean 3-space
Mehmet
Önder
Delibekirli Village
author
Onur
Kaya
Manisa Celal Bayar University
author
text
article
2017
eng
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.
Caspian Journal of Mathematical Sciences (CJMS)
University of Mazandaran
1735-0611
6
v.
1
no.
2017
31
46
http://cjms.journals.umz.ac.ir/article_1637_3dfbcc7f597530eed764d94b1e14a96f.pdf
dx.doi.org/10.22080/cjms.2017.1637
On the determination of eigenvalues for differential pencils with the turning point
A.
Neamaty
University of Mazandaran
author
Y.
Khalili
Department of Basic Sciences, Sari
Agricultural Sciences and Natural Resources University, Sari, Iran
author
text
article
2017
eng
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.
Caspian Journal of Mathematical Sciences (CJMS)
University of Mazandaran
1735-0611
6
v.
1
no.
2017
47
53
http://cjms.journals.umz.ac.ir/article_1644_cccdcc4d07e2d9aa5a28063a8e403ecf.pdf
dx.doi.org/10.22080/cjms.2017.1644
A local approach to the entropy of countable fuzzy partitions
R.
R. Ghasemkhani
Department of Mathematics, Faculty of Science
University of Jiroft, Jiroft, Iran. 78671-61167
author
u.
Mohammadi
Department of Mathematics, Faculty of Science
University of Jiroft, Jiroft, Iran. 78671-61167
author
text
article
2017
eng
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.
Caspian Journal of Mathematical Sciences (CJMS)
University of Mazandaran
1735-0611
6
v.
1
no.
2017
54
61
http://cjms.journals.umz.ac.ir/article_1646_b05fc6a1751fa4d5ce50e2c2e41b8460.pdf
dx.doi.org/10.22080/cjms.2017.1646