exponential approximation

In this paper,the authors study approximate exponential metric and prove that the second approximate exponential metric F=α+β+β22α+β36α2 is locally projectively flat if and only ifα is projectively flat and β is parallel with respect to α,where α=aijyiyj,β=biyi.

研究了近似指数度量并得到二阶近似指数度量射影平坦的充要条件是α射影平坦,β关于α平行。