Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Preheating in Derivatively-Coupled Inflation Models   We study preheating in theories where the inflaton couples derivatively to
scalar and gauge fields. Such couplings may dominate in natural models of
inflation, in which the flatness of the inflaton potential is related to an
approximate shift symmetry of the inflaton. We compare our results with
previously studied models with non-derivative couplings. For sufficiently heavy
scalar matter, parametric resonance is ineffective in reheating the universe,
because the couplings of the inflaton to matter are very weak. If scalar matter
fields are light, derivative couplings lead to a mild long-wavelength
instability that drives matter fields to non-zero expectation values. In this
case however, long-wavelength fluctuations of the light scalar are produced
during inflation, leading to a host of cosmological problems. In contrast,
axion-like couplings of the inflaton to a gauge field do not lead to production
of long-wavelength fluctuations during inflation. However, again because of the
weakness of the couplings to the inflaton, parametric resonance is not
effective in producing gauge field quanta.

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The categories of this paper are: cond-mat
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The categories of this paper are: q-fin
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The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
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The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
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The categories of this paper are: cmp-lg
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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: bayes-an
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The categories of this paper are: adap-org
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The categories of this paper are: funct-an
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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: math
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The categories of this paper are: hep-th