Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Decoherence of Photons in the Presence of Hidden U(1)s   Many extensions of the standard model predict the existence of hidden sectors
that may contain unbroken abelian gauge groups. We argue that in the presence
of quantum decoherence photons may convert into hidden photons on sufficiently
long time scales and show that this effect is strongly constrained by CMB and
supernova data. In particular, Planck-scale suppressed decoherence scales D ~
E^2/M_Pl (characteristic for non-critical string theories) are incompatible
with the presence of even a single hidden U(1). The corresponding bounds on the
decoherence scale are four orders of magnitude stronger than analogous bounds
derived from solar and reactor neutrino data and complement other bounds
derived from atmospheric neutrino data.

1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga