Abstract:
We introduce the notion of contactly geodesic transformation of
the metric of an almost-contact metric structure as a contact
analog of holomorphically geodesic transformations of the metric
of an almost-Hermitian structure.
A series of invariants of such
transformations is obtained.
We prove that such transformations
preserve the normality property of an almost-contact metric
structure.
We prove that cosymplectic and Sasakian manifolds, as
well as Kenmotsu manifolds, do not admit nontrivial contactly
geodesic transformations of the metric, which is a contact analog
of the well-known result for Kählerian manifolds due to Westlake
and Yano.