http://arxiv.org/abs/2005.07563

We study the energy distribution and equation of state of the universe between the end of inflation and the onset of radiation domination (RD), considering observationally consistent single-field inflationary scenarios, with a potential ‘flattening’ at large field values, and a monomial shape $V(\phi) \propto |\phi|^p$ around the origin. We include a quadratic interaction $g^2\phi^2X^2$ between the inflaton $\phi$ and a light scalar ‘daughter’ field $X$, as a proxy for (p)reheating. We capture the non-perturbative and non-linear nature of the system dynamics with lattice simulations, obtaining that: $i)$ the final energy transferred to $X$ depends only on $p$, not on $g^2$; $ii)$ the final transfer of energy is always negligible for $2 \leq p < 4$, and of order $\sim 50\%$ for $p \geq 4$; $iii)$ the system goes at late times to matter-domination for $p = 2$, and always to RD for $p > 2$. In the latter case we calculate the number of e-folds until RD, significantly reducing the uncertainty in the inflationary observables $n_s$ and $r$.

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S. Antusch, D. Figueroa, K. Marschall, et. al.
Mon, 18 May 20
3/43

Comments: 5 pages + references, 3 figures