ORIGINAL_ARTICLE
Warped product and quasi-Einstein metrics
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
http://cjms.journals.umz.ac.ir/article_1635_cb0159ef48f22f008d96a7c16c50d1f2.pdf
2017-01-01T11:23:20
2018-08-16T11:23:20
1
8
10.22080/cjms.2017.1635
warped product
quasi-Einstein space
compact base manifolds
Buddhadev
Pal
pal.buddha@gmail.com
true
1
University of Calcutta
University of Calcutta
University of Calcutta
LEAD_AUTHOR
Arindam
Bhattacharyya
bhattachar1968@yahoo.co.in
true
2
Jadavpur University
Jadavpur University
Jadavpur University
AUTHOR
Santu
Dey
santu.mathju@gmail.com
true
3
Jadavpur University
Jadavpur University
Jadavpur University
AUTHOR
ORIGINAL_ARTICLE
Reduction of Differential Equations by Lie Algebra of Symmetries
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.
http://cjms.journals.umz.ac.ir/article_1636_cb984d580c423c494eedb52c01845388.pdf
2017-01-01T11:23:20
2018-08-16T11:23:20
9
30
10.22080/cjms.2017.1636
Symmetry
Lie Group
Invariance
S. Reza
Hejazi
ra.hejazi@gmail.com
true
1
Department of Mathematics, University of Shahrood, Shahrood, Semnan, Iran.
Department of Mathematics, University of Shahrood, Shahrood, Semnan, Iran.
Department of Mathematics, University of Shahrood, Shahrood, Semnan, Iran.
LEAD_AUTHOR
ORIGINAL_ARTICLE
Characterizations of Slant Ruled Surfaces in the Euclidean 3-space
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.
http://cjms.journals.umz.ac.ir/article_1637_3dfbcc7f597530eed764d94b1e14a96f.pdf
2017-01-01T11:23:20
2018-08-16T11:23:20
31
46
10.22080/cjms.2017.1637
Slant ruled surface
Frenet frame
Conical curvature
Differential equation
Mehmet
Önder
mehmetonder197999@gmail.com
true
1
Delibekirli Village
Delibekirli Village
Delibekirli Village
LEAD_AUTHOR
Onur
Kaya
onur.kaya@cbu.edu.tr
true
2
Manisa Celal Bayar University
Manisa Celal Bayar University
Manisa Celal Bayar University
AUTHOR
ORIGINAL_ARTICLE
On the determination of eigenvalues for differential pencils with the turning point
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.
http://cjms.journals.umz.ac.ir/article_1644_cccdcc4d07e2d9aa5a28063a8e403ecf.pdf
2017-01-01T11:23:20
2018-08-16T11:23:20
47
53
10.22080/cjms.2017.1644
Eigenvalues
Differential pencil
Turning point
A.
Neamaty
neamaty7@gmail.com
true
1
University of Mazandaran
University of Mazandaran
University of Mazandaran
LEAD_AUTHOR
Y.
Khalili
true
2
Department of Basic Sciences, Sari
Agricultural Sciences and Natural Resources University, Sari, Iran
Department of Basic Sciences, Sari
Agricultural Sciences and Natural Resources University, Sari, Iran
Department of Basic Sciences, Sari
Agricultural Sciences and Natural Resources University, Sari, Iran
AUTHOR
ORIGINAL_ARTICLE
A local approach to the entropy of countable fuzzy partitions
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.
http://cjms.journals.umz.ac.ir/article_1646_b05fc6a1751fa4d5ce50e2c2e41b8460.pdf
2017-01-01T11:23:20
2018-08-16T11:23:20
54
61
10.22080/cjms.2017.1646
Local entropy
countable partition
local diameter
R.
R. Ghasemkhani
true
1
Department of Mathematics, Faculty of Science
University of Jiroft, Jiroft, Iran. 78671-61167
Department of Mathematics, Faculty of Science
University of Jiroft, Jiroft, Iran. 78671-61167
Department of Mathematics, Faculty of Science
University of Jiroft, Jiroft, Iran. 78671-61167
AUTHOR
u.
Mohammadi
u.mohamadi@ujiroft.ac.ir
true
2
Department of Mathematics, Faculty of Science
University of Jiroft, Jiroft, Iran. 78671-61167
Department of Mathematics, Faculty of Science
University of Jiroft, Jiroft, Iran. 78671-61167
Department of Mathematics, Faculty of Science
University of Jiroft, Jiroft, Iran. 78671-61167
LEAD_AUTHOR