Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Equation of State and Duration to Radiation Domination After
  Inflation   We calculate the equation of state after inflation and provide an upper bound
on the duration before radiation domination by taking the nonlinear dynamics of
the fragmented inflaton field into account. A broad class of single-field
inflationary models with observationally consistent flattening of the potential
at a scale $M$ away from the origin, $V(\phi)\propto |\phi|^{2n}$ near the
origin, and where the couplings to other fields are ignored are included in our
analysis. We find that the equation of state parameter $w\rightarrow 0$ for
$n=1$ and $w\rightarrow 1/3$ (after sufficient time) for $n\gtrsim 1$. We
calculate how the number of $e$-folds to radiation domination depends on both
$n$ and $M$ when $M\sim m_{\rm pl}$, whereas when $M\ll m_{\rm pl}$, we find
that the duration to radiation domination is negligible. Our results are
explained in terms of a linear instability analysis in an expanding universe,
scaling arguments, and are supported by detailed 3+1 dimensional lattice
simulations. We show how our work significantly reduces the uncertainty in
inflationary observables, even after including couplings to additional light
fields.

18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org