Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Double scattering of light from biophotonic nanostructures with
  short-range order   We investigate the physical mechanism for color production by isotropic
nanostructures with short-range order in bird feather barbs. While the primary
peak in optical scattering spectra results from constructive interference of
singly-scattered light, many species exhibit secondary peaks with distinct
characteristic. Our experimental and numerical studies show that these
secondary peaks result from double scattering of light by the correlated
structures. Without an analog in periodic or random structures, such a
phenomenon is unique for short-range ordered structures, and has been widely
used by nature for non-iridescent structural coloration.

33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph