Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Criticality and Averaging in Cosmology   We propose comparing cosmological solutions in terms of their total spatial
volumes $V(\tau)$ as functions of proper time $\tau$, assuming synchronous
gauge, and with this intention evaluate the variations of $V(\tau)$ about the
Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) solutions for dust. This can be
done successfully in a simple manner without solving perturbation equations. In
particular, we find that first variations vanish with respect to all directions
which do not possess homogeneity and isotropy preserving components; in other
words, every FLRW solution is a {\it critical point} for $V(\tau)$ in the
properly restricted subspace of the space of solutions. This property may
support a validity of the interpretation of the FLRW solutions as constituting
an averaged model. We also briefly investigate the second variations of
$V(\tau)$.

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The categories of this paper are: math
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The categories of this paper are: atom-ph
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The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
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The categories of this paper are: quant-ph
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The categories of this paper are: stat
18
The categories of this paper are: econ
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The categories of this paper are: hep-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: acc-phys
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
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The categories of this paper are: q-alg
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The categories of this paper are: eess