Computation of Gravitational Particle Production Using Adiabatic Invariants

Understand

Analytic and numerical techniques are presented for computing gravitational production of scalar particles in the limit that the inflaton mass is much larger than the Hubble expansion rate at the end of inflation.

• These techniques rely upon adiabatic invariants and time modeling of a typical inflaton field which has slow and fast time variation components.
• A faster computation time for numerical integration is achieved via subtraction of slowly varying components that are ultimately exponentially suppressed.
• The fast oscillatory remnant results in production of scalar particles with a mass larger than the inflationary Hubble expansion rate through a mechanism analogous to perturbative particle scattering.