Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photon trajectories in incoherent atomic radiation trapping as Levy
  flights   Photon trajectories in incoherent radiation trapping for Doppler, Lorentz and
Voigt line shapes under complete frequency redistribution are shown to be Levy
flights. The jump length (r) distributions display characteristic long tails.
For the Lorentz line shape, the asymptotic form is a strict power-law r^{-3/2}
while for Doppler the asymptotic is r^{-2} (ln r)^{-1/2}. For the Voigt
profile, the asymptotic form has always a Lorentz character, but the trajectory
is a self-affine fractal with two characteristic Hausdorff scaling exponents.

23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs