Oscillons after Inflation

Mustafa A. Amin, Richard Easther, Hal Finkel, Raphael Flauger, and Mark P. Hertzberg

Phys. Rev. Lett. 108, 241302 – Published 14 June 2012

Abstract

Oscillons are massive, long-lived, localized excitations of a scalar field. We show that in a class of well-motivated single-field models, inflation is followed by self resonance, leading to copious oscillon generation and a lengthy period of oscillon domination. These models are characterized by an inflaton potential which has a quadratic minimum and is shallower than quadratic away from the minimum. This set includes both string monodromy models and a class of supergravity inspired scenarios and is in good agreement with the current central values of the concordance cosmology parameters. We assume that the inflaton is weakly coupled to other fields so as not to quickly drain energy from the oscillons or prevent them from forming. An oscillon-dominated universe has a greatly enhanced primordial power spectrum on very small scales relative to that seen with a quadratic potential, possibly leading to novel gravitational effects in the early Universe.

Received 22 June 2011

DOI:https://doi.org/10.1103/PhysRevLett.108.241302

Authors & Affiliations

Mustafa A. Amin¹, Richard Easther², Hal Finkel², Raphael Flauger², and Mark P. Hertzberg³

¹Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
²Department of Physics, Yale University, New Haven, Connecticut 06520, USA
³SITP and KIPAC, Department of Physics, Stanford University, Stanford, California 94305, USA