Hamiltonian systems on almost cosymplectic manifolds

We determine the Hamiltonian vector field on an odd dimensional manifold endowed with almost cosymplectic structure. This is a generalization of the corresponding Hamiltonian vector field on manifolds with almost transitive contact structures, which extends the contact Hamiltonian systems. Applications are presented to the equations of motion on a particular five-dimensional manifold, the extended Siegel-Jacobi upper-half plane $\tilde{\mathcal{X}}^J_1$. The $\tilde{\mathcal{X}}^J_1$ manifold is endowed with a generalized transitive almost cosymplectic structure, an almost cosymplectic structure, more general than transitive almost contact structure and cosymplectic structure.The equations of motion on $\tilde{\mathcal{X}}^J_1$ extend the Riccati equations of motion on the four-dimensional Siegel-Jacobi manifold $\mathcal{X}^J_1$ attached to a linear Hamiltonian in the generators of the real Jacobi group $G^J_1(\mathbb{R})$.Comment: 27 pages, Latex, amsart, AMS fonts, the appendix is systematized, one more reference is added, some typos are correcte