Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cooperative spontaneous emission via renormalization approach: Classical
  versus semi-classical effects   We address the many-atom emission of a dilute cloud of two-level atoms
through a renormalized perturbation theory. An analytical solution for the
truncated coupled-dipole equations is derived, which contains an effective
spectrum associated to the initial conditions. Our solution is able to
distinguish precisely classical from semi-classical predictions for large
atomic ensembles. This manifests as a reduction of the cooperativity in the
radiated power for higher atomic excitation, in disagreement with the fully
classical prediction from linear optics. Moreover, the second-order cooperative
emission appears accurate over several single atom lifetimes and for
interacting regimes stronger than those permitted in conventional perturbation
theory. We can compute the semiclassical dynamics of hundred thousand of
interacting atoms with ordinary computational resources, which makes our
formalism particularly promising to probe the nonlinear dynamics of quantum
many-body systems that emerge from cumulant expansions.

15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc