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摘要: |
本文研究和刻画了射影Ricci平坦的Kropina度量.利用Kropina度量的S-曲率和Ricci曲率的公式,得到了Kropina度量的射影Ricci曲率公式.在此基础上得到了Kropina度量是射影Ricci平坦度量的充分必要条件.进一步,作为自然的应用,本文研究和刻画了由一个黎曼度量和一个具有常数长度的Killing 1-形式定义的射影Ricci平坦的Kropina度量,也刻画了具有迷向S-曲率的射影Ricci平坦的Kropina度量.在这种情形下,Kropina度量是Ricci平坦度量. |
关键词: 芬斯勒度量 Kropina度量 Ricci曲率 S-曲率 射影Ricci曲率 |
DOI: |
分类号:O186.1 |
基金项目:Supported by the National Natural Science Foundation of China (11371386) and the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement (317721). |
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ON PROJECTIVE RICCI FLAT KROPINA METRICS |
CHENG Xin-yue,MA Xiao-yu,SHEN Yu-ling
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Abstract: |
In this paper, we study and characterize projective Ricci flat Kropina metrics. By using the formulas of S-curvature and Ricci curvature for Kropina metrics, we obtain the formula of the projective Ricci curvature for Kropina metrics. Based on this, we obtain the necessary and su-cient conditions for Kropina metrics to be projective Ricci flat metrics. Further, as a natural application, we study and characterize projective Ricci flat Kropina metrics deflned by a Riemannian metric and a Killing 1-form of constant length. We also characterize projective Ricci flat Kropina metrics with isotropic S-curvature. In this case, the Kropina metrics are Ricci flat metrics. |
Key words: Finsler metric Kropina metrics Ricci curvature S-curvature projective Ricci curvature |