1.
Proc Natl Acad Sci U S A
; 116(29): 14501-14504, 2019 07 16.
Artigo
em Inglês
| MEDLINE
| ID: mdl-31262829
RESUMO
A half-geodesic is a closed geodesic realizing the distance between any pair of its points. All geodesics in a round sphere are half-geodesics. Conversely, this paper establishes that Riemannian spheres with all geodesics closed and sufficiently many half-geodesics are round.