Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Parametric Luminescence of Microcavity Polaritons   The spectral and dispersive emission properties are analytically determined
for the two-dimensional system of exciton-polaritons in microcavities excited
by a resonant and coherent optical pump. New collective excitations result from
the anomalous coupling between one generic polariton state and its idler,
created by the scattering of two pumped polaritons. The corresponding
parametric correlation is stimulated by the emitter and idler populations and
drives very efficiently the luminescence. The intrinsic properties of the
collective excitations determine a peculiar emission pattern.

22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph