Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Out of Equilibrium Non-perturbative Quantum Field Dynamics in
  Homogeneous External Fields   The quantum dynamics of the symmetry broken lambda (Phi^2)^2 scalar field
theory in the presence of an homogeneous external field is investigated in the
large N limit. We choose as initial state the ground state for a constant
external field J .The sign of the external field is suddenly flipped from
  J to - J at a given time and the subsequent quantum dynamics calculated.
Spinodal instabilities and parametric resonances produce large quantum
fluctuations in the field components transverse to the external field. This
allows the order parameter to turn around the maximum of the potential for
intermediate times. Subsequently, the order parameter starts to oscillate near
the global minimum for external field - J, entering a novel quasi-periodic
regime.

29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio