Oscillons after Inflation
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.
- Publication:
-
Physical Review Letters
- Pub Date:
- June 2012
- DOI:
- 10.1103/PhysRevLett.108.241302
- arXiv:
- arXiv:1106.3335
- Bibcode:
- 2012PhRvL.108x1302A
- Keywords:
-
- 98.80.Cq;
- Particle-theory and field-theory models of the early Universe;
- Astrophysics - Cosmology and Extragalactic Astrophysics;
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- E-Print:
- v2: clarifications added in text in response to comments from the referees, references updated but results remain unchanged. For visualizations, see http://www.mit.edu/~mamin/oscillons.html and http://easther.physics.yale.edu/Richard_Easther/Scalar_Fields.html . Code available at http://easther.physics.yale.edu/Richard_Easther/Downloads.html