局部对称空间上的闭测地线

The Closed Geodesics in a Compact Local Symmetric Space

讨论了曲率定号的完备黎曼流形上的平行向量场与Jacobi场之间的关系;证明了紧致的偶数维具非负曲率的非单连通局部对称空间上存在无穷多条长度一样的闭测地线.

The paper discusses the relations between parallel vector fields and Jacobi fields in a complete Riemannian manifold, and proves that there exists infinite closed geodesics in a local symmetric space which is orientable, compact, nonsimply connected and with nonnegative sectional curvature.