Post-inflationary preheating with weak coupling

Abstract

Particle production in the background of an external classical oscillating field is a key process describing the stage of preheating after inflation. For sufficiently strong couplings between the inflaton and matter fields, this process is known to proceed non-perturbatively. Parametric resonance plays crucial role for bosonic fields in this case, and the evolution of the occupation numbers for fermions is non-perturbative as well. In the Minkowski space, parametric resonance for bosons and non-perturbative effects for fermions would still persist even in the case of weak coupling. In particular, the energy density of created bosons would grow exponentially with time. However, the situation is quite different in the expanding universe. We give a simple demonstration how the conditions of the expanding universe, specifically, redshift of the field modes, lead to the usual perturbative expressions for particle production by an oscillating inflaton in the case of weak couplings. The results that we obtain are relevant and fully applicable to the Starobinsky model of inflation.

17 pages; Phys. Lett. B 733, 2014

References in corpus (2)

• Constraining f(R) Gravity as a Scalar Tensor Theory
• Scalaron the mighty: producing dark matter and baryon asymmetry at reheating

Cited by in corpus (13)

• A Critical Review of Classical Bouncing Cosmologies
• Gravitational Particle Production in Oscillating Background and Its Cosmological Implications
• UV Freeze-in in Starobinsky Inflation
• Reheating processes after Starobinsky inflation in old-minimal supergravity
• Inflaton dark matter from incomplete decay
• Magnetogenesis during inflation and preheating in the Starobinsky model
• Light scalaron as dark matter
• Irreversible thermodynamical description of warm inflationary cosmological models
• No quasi-stable scalaron lump forms after $R^2$ inflation
• Natural Braneworld Inflation in Light of Recent Results from Planck and BICEP2
• On the Conformal Frames in $f(R)$ Gravity
• Scalaron dark matter and the thermal history of the universe
• Revisiting the sphaleron and axion production rates in QCD at high temperatures