摘要
This paper solves the isometry problem between two indefinite metrics by using exterior differential systems. We prove that an indefinite metric is either rigid, admits a one parameter group of isometries (rotation like surfaces), or admits a three parameter group of isometries (K=constant).
This paper solves the isometry problem between two indefinite metrics by using exterior differential systems. We prove that an indefinite metric is either rigid, admits a one parameter group of isometries (rotation like surfaces), or admits a three parameter group of isometries (K=constant).
基金
the National Natural Science Foundationof China (No.1970 10 17)