Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 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.

7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org