摘要
本文研究了一类具有奇性的芬斯勒度量——广义Kropina度量.文中给出了刻画广义Kropina度量的等价方程.进一步的研究工作表明,由共形1-形式β构造的Kropina度量是对偶平坦的,当且仅当其中的黎曼度量α是欧氏的,且该1-形式β是常向量场.还给出了一类很有意思的非平凡局部对偶平坦Kropina度量的例子.
In this paper,a class of Finsler metrics with singularity,called general Kropina metrics,are studied.Equivalent equations are given to characterize locally dually flat general Kropina metrics.Further research shows that a Kropina metric is dually flat with the conformal1-form β if and only if it is induced from a Euclidean metric α and a constant vector field β.A class of interesting non-trivial locally dually flat Kropina metrics is also given as an example.
引文
[1]Asanov,G.,Finsler Geometry,Relativity and Gauge Theories,Dordrecht:D.Reidel Publishing Company,1985.
[2]Cheng,X.Y.and Shen,Z.M.,Finsler Geometry—An Approach via Randers Spaces,Beijing:Science Press,2012.
[3]Cheng,X.Y.,Shen,Z.M.and Zhou,Y.S.,On locally dually flat Randers metrics,Intern.Math.J.,2010,21(11):1531-1543.
[4]Kropina,V.,Projective two-dimensional Finsler spaces with a special metric,Trudy Sem.Vektor.Tenzor.Anal.,1961,11:277-292(in Russian).
[5]Shen,Z.M.,Riemannian-Finsler geometry with applications to information geometry,Chinese Ann.Math.Ser.B,2006,27(1):73-94.
[6]Xia,Q.L.,On locally dually flat(α,β)-metrics,Differential Geom.Appl,2011,29(2):233-243.
[7]Yajima,T.and Nagahama,H.,Kawaguchi space,Zermelo's condition and seismic ray path,Nonlinear Anal.Real World Appl.,2007,8(1):130-135.
[8]Yu,C.T.,On dually flat Randers metrics,Nonlinear Anal,2014,95:146-155.
[9]Zhang,X.L.,On projectively flat Kropina metrics,2013,arXiv:1304.1612.