Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A smooth bouncing cosmology with scale invariant spectrum   We present a bouncing cosmology which evolves from the contracting to the
expanding phase in a smooth way, without developing instabilities or
pathologies and remaining in the regime of validity of 4d effective field
theory. A nearly scale invariant spectrum of perturbations is generated during
the contracting phase by an isocurvature scalar with a negative exponential
potential and then converted to adiabatic. The model predicts a slightly blue
spectrum, n_S >~ 1, no observable gravitational waves and a high (but model
dependent) level of non-Gaussianities with local shape. The model represents an
explicit and predictive alternative to inflation, although, at present, it is
clearly less compelling.

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The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
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The categories of this paper are: q-alg
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: stat
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The categories of this paper are: math-ph
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
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The categories of this paper are: comp-gas
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The categories of this paper are: patt-sol
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The categories of this paper are: acc-phys
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The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin