On the Geometry of Locally Conformally Almost Cosymplectic Manifolds

We obtain the complete group of structure equations of a locally conformally almost cosymplectic structure (an $lc\mathscr{AC_S}$-structure in what follows) and compute the components of the Riemannian curvature tensor on the space of the associated $G$-structure. Normal $lc\mathscr{AC_S}$-structures are studied in more detail. In particular, we prove that the contact analogs of A. Gray's second and third curvature identities hold on normal $lc\mathscr{AC_S}$-manifolds, while the contact analog of A. Gray's first identity holds if and only if the manifold is cosymplectic.