Inflaton fragmentation: Emergence of pseudo-stable inflaton lumps (oscillons) after inflation

TL;DR

This paper studies how inflaton fields fragment after inflation to form various pseudo-stable localized structures called oscillons, predicting their abundance and conditions for formation through analytic and numerical methods.

Contribution

It provides new analytic estimates and numerical simulations of oscillon formation from inflaton fragmentation in different dimensions, detailing their properties and energy contribution.

Findings

Oscillons can account for about 80% of inflaton energy density.

Both small 'sech' and large 'flat-topped' oscillons are observed.

Predicted oscillon densities match simulation results.

Abstract

We investigate the emergence of large, localized, pseudo-stable configurations (oscillons) from inflaton fragmentation at the end of inflation. We predict the number density of large oscillons, and the conditions necessary for their emergence in a class of inflationary models. Analytic estimates are provided for a 3+1 and 1+1-dimensional universe. We test our predictions with detailed numerical simulations in 1+1-dimensions. We see a zoo of oscillons emerging from the simulations, including the usual small amplitude "sech" oscillons as well as large "flat-topped" oscillons. The emergent oscillons account for approximately 80 per cent of the energy density of the inflaton.