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 &Ouml;nder 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 de nes 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