关于推广的Douglas-Weyl度量     

尧克刚  程新跃  薛善增 《西南大学学报》2009,31(2)

研究Finsler度量中一类非常重要的几何量--推广的Douglas-Weyl度量.得到了n维(n≥3)流形上的Finsler度量是具有弱迷向旗曲率的推广的Douglas-Weyl度量的充分必要条件.  相似文献   

具有某些非黎曼曲率性质的Douglas度量     

薛善增  程新跃  尧克刚 《西南大学学报》2009,31(6)

研究完备的Douglas空间(M,F),证明了如果其Cartan张量是有界的,且满足H=0和Ejk,l/m=0,则F为Berwald度量,其中E为F的平均Berwald曲率,H为刻划E沿测地线的变化率的几何量.

Abstract：

A complete Douglas space (M, F) is studied. It is proved that if the Cartan torsion of a complete Douglas space (M, F) is bounded and F satisfies that H = 0 and Ejk. l\m = 0, then F is a Berwald metric.Here E is the mean Berwald curvature of F, and H is the geometric quantity which characterizes the rate of the change of E along geodesics.  相似文献