Isotropic manifold
(重定向自Isotropic space)
In mathematics, an isotropic manifold is a manifold in which the geometry does not depend on directions. Formally, we say that a Riemannian manifold is isotropic if for any point
and unit vectors
, there is an isometry
of
with
and
. Every complete isotropic manifold is homogeneous, i.e. for any
there is an isometry
of
with
This can be seen by considering a geodesic
from
to
and taking the isometry which fixes
and maps
to