Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Transmission, reflection and localization in a random medium with
  absorption or gain   We study reflection and transmission of waves in a random tight-binding
system with absorption or gain for weak disorder, using a scattering matrix
formalism. Our aim is to discuss analytically the effects of absorption or gain
on the statistics of wave transport. Treating the effects of absorption or gain
exactly in the limit of no disorder, allows us to identify short- and long
lengths regimes relative to absorption- or gain lengths, where the effects of
absorption/gain on statistical properties are essentially different. In the
long-lengths regime we find that a weak absorption or a weak gain induce
identical statistical corrections in the inverse localization length, but lead
to different corrections in the mean reflection coefficient. In contrast, a
strong absorption or a strong gain strongly suppress the effect of disorder in
identical ways (to leading order), both in the localization length and in the
mean reflection coefficient.

27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph