Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Alfven modes driven non-linearly by metric perturbations in anisotropic
  magnetized cosmologies   We consider anisotropic magnetized cosmologies filled with conductive plasma
fluid and study the implications of metric perturbations that propagate
parallel to the ambient magnetic field. It is known that in the first order
(linear) approximation with respect to the amplitude of the perturbations no
electric field and density perturbations arise. However, when we consider the
non-linear coupling of the metric perturbations with their temporal
derivatives, certain classes of solutions can induce steeply increasing in time
electric field perturbations. This is verified both numerically and
analytically. The source of these perturbations can be either high-frequency
quantum vacuum fluctuations, driven by the cosmological pump field, in the
early stages of the evolution of the Universe or astrophysical processes or a
non-linear isotropization process of an initially anisotropic cosmological
spacetime.

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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ph
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The categories of this paper are: stat
3
The categories of this paper are: physics
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
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The categories of this paper are: supr-con
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The categories of this paper are: quant-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: econ
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The categories of this paper are: astro-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat