Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strongly coupled quantum field theory   We analyze numerically a two-dimensional $\lambda\phi^4$ theory showing that
in the limit of a strong coupling $\lambda\to\infty$ just the homogeneous
solutions for time evolution are relevant in agreement with the duality
principle in perturbation theory as presented in [M.Frasca, Phys. Rev. A {\bf
58}, 3439 (1998)], being negligible the contribution of the spatial varying
parts of the dynamical equations. A consequence is that the Green function
method works for this non-linear problem in the large coupling limit as in a
linear theory. A numerical proof is given for this. With these results at hand,
we built a strongly coupled quantum field theory for a $\lambda\phi^4$
interacting field computing the first order correction to the generating
functional. Mass spectrum of the theory is obtained turning out to be that of a
harmonic oscillator with no dependence on the dimensionality of spacetime. The
agreement with the Lehmann-K\"allen representation of the perturbation series
is then shown at the first order.

21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys