Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Luminosity distance for Born-Infeld electromagnetic waves propagating in
  a cosmological magnetic background   Born-Infeld electromagnetic waves interacting with a static magnetic
background are studied in an expanding universe. The non-linear character of
Born-Infeld electrodynamics modifies the relation between the energy flux and
the distance to the source, which gains a new dependence on the redshift that
is governed by the background field. We compute the luminosity distance as a
function of the redshift and compare with Maxwellian curves for supernovae type
Ia.

14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th