Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonsingular bouncing cosmology from general relativity   We investigate a particular type of classical nonsingular bouncing cosmology,
which results from general relativity if we allow for degenerate metrics. The
simplest model has a matter content with a constant equation-of-state parameter
and we get the modified Hubble diagrams for both the luminosity distance and
the angular diameter distance. Based on these results, we present a
Gedankenexperiment to determine the length scale of the spacetime defect which
has replaced the big bang singularity. A possibly more realistic model has an
equation-of-state parameter which is different before and after the bounce.
This last model also provides an upper bound on the defect length scale.

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The categories of this paper are: math
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
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The categories of this paper are: cs
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom