Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: PVLAS Experiment: Some Astrophysical Consequences   The birefringent effects of photon-pseudoscalar boson (Goldstone) particle
mixing in intergalactic magnetic field are calculated for cosmological objects.
We use the recent results of PVLAS collaboration that reported recently the
observation of a rotation of the polarization plane of light propagating
through a transverse static magnetic field. Such results which were
interpretated as arising due to conversion of photon into pseudoscalar with
coupling strength $g_{a\gamma}\sim 4\times 10^{-6} GeV^{-1}$ allows us to
estimate the intergalactic magnetic field magnitude as $\sim 10^{-16} G$ based
on Hatsemekers et al. observations of extreme-scale alignments of quasar
polarization vectors. We have analyzed some additional results of astronomical
observations that could be explained by axion interpretation of the PVLAS data:
a sharp steepening of the QSO continuum short ward of $\simeq 1100$\AA,
observed circular polarization of AGNs and QSOs, discrepancy between observed
intrinsic polarization of stars in the Local Bubble and stellar spectral
classification. The observed polarization of stars in the Local Bubble can't be
explained by interstellar origin.

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The categories of this paper are: cs
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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
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The categories of this paper are: atom-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-ex
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The categories of this paper are: cmp-lg
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The categories of this paper are: cond-mat
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The categories of this paper are: econ
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The categories of this paper are: hep-ph
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The categories of this paper are: chem-ph