Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On stability of the Kasner solution in quadratic gravity   We consider dynamics of a flat anisotropic Universe filled by a perfect fluid
near a cosmological singularity in quadratic gravity. Two possible regimes are
described -- the Kasner anisotropic solution and an isotropic "vacuum
radiation" solution which has three sub cases depending on whether the equation
of state parameter $w$ is bigger, smaller or equals to $1/3$. Initial
conditions for numerical integrations have been chosen near General Relativity
anisotropic solution with matter (Jacobs solution). We have found that for such
initial conditions there is a range of values of coupling constants so that the
resulting cosmological singularity is isotropic.

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The categories of this paper are: q-fin
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
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The categories of this paper are: q-bio
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The categories of this paper are: econ
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The categories of this paper are: acc-phys
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The categories of this paper are: comp-gas
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The categories of this paper are: chem-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: solv-int
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The categories of this paper are: stat
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-th
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The categories of this paper are: patt-sol
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The categories of this paper are: cs
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The categories of this paper are: nucl-th