Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analytical solution for Klein-Gordon equation and action function of the
  solution for Dirac equation in counter-propagating laser waves   Nonperturbative calculation of QED processes participated by a strong
electromagnetic field, especially provided by strong laser facilities at
present and in the near future, generally resorts to the Furry picture with the
usage of analytical solutions of the particle dynamical equation, such as the
Klein-Gordon equation and Dirac equation. However only for limited field
configurations such as a plane-wave field could the equations be solved
analytically. Studies have shown significant interests in QED processes in a
strong field composed of two counter-propagating laser waves, but the exact
solutions in such a field is out of reach. In this paper, inspired by the
observation of the structure of the solutions in a plane-wave field, we develop
a new method and obtain the analytical solution for the Klein-Gordon equation
and equivalently the action function of the solution for the Dirac equation in
this field, under a largest dynamical parameter condition that there exists an
inertial frame in which the particle free momentum is far larger than the other
field dynamical parameters. The applicable range of the new solution is
demonstrated and its validity is proven clearly. The result has the advantage
of Lorentz covariance, clear structure and close similarity to the solution in
a plane-wave field, and thus favors convenient application.

28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc