conjugate points
Let be a manifold on which a notion of geodesic
is defined. (For instance, could be a Riemannian manifold
, could be a manifold with affine connection
, or could be a Finsler space.)
Two distinct points, and of are said to be conjugate points if there exist two or more distinct geodesic segments having and as endpoints.
A simple example of conjugate points are the north and south poles of a sphere (endowed with the usual metric of constant curvature) — every meridian
is a geodesic segment having the poles as endpoints.