Periodical Solutions of Poisson-Gradient Dynamical Systems with   Periodical Potential
  The main purpose of this paper is the study of the action that produces Poisson-gradient systems and their multiple periodical solutions. The Section 1 establishes the basic tools.   The section 2 underlines conditions in which the action $\phi (u) = \displaystyle\displaystyle\int_{T_{0}}[ \displaystyle% \displaystyle{1/2}| \displaystyle\displaystyle\frac{\partial u}{% \partial t}| ^{2}+F(t,u(t)) ] dt^{1}\wedge >...\wedge dt^{p}$, that produces the Poisson-gradient systems, is continuous, and some conditions in which the general action $\phi (u) = \displaystyle\displaystyle\int_{T_{0}}L(t,u(t), \displaystyle\displaystyle\frac{\partial u}{\partial t}(t)) dt^{1}\wedge >...\wedge dt^{p}$ is continuously differentiable.   The Section 3 studies the multiple periodical solutions of a Poisson-gradient system in the case when the potential function $F$ has a spatial periodicity. 
Constantin Udriste, Iulian Duca