Nonperturbative evaluation of quantum particle production in parametric resonance enhanced by noise

TL;DR

This paper presents nonperturbative numerical methods to evaluate quantum particle production during inflation, demonstrating significant enhancement due to noise effects using two renormalization group approaches.

Contribution

It introduces two nonperturbative renormalization group formulations for accurately calculating particle production in noisy inflationary models.

Findings

Particle production is significantly enhanced by noise effects.

Two numerical methods show consistent results.

Provides quantitative tools for inflationary cosmology studies.

Abstract

Numerical studies are reported to support the idea to explain the particle production in late inflationary era based on the parametric resonance with a noise effect. Two nonperturbative renormalization group formulations are used to numerically calculate the time evolution of particle numbers. Firstly, the dynamical renormalization group (DRG) method is applied to sum up the secular contributions. Secondly, we derive an exact evolution equation of the particle number which turned out to be possible surprisingly owing to the presence of the noise effect. Our numerical results show a drastic enhancement of the particle production in agreement with earlier works qualitatively. A comparison is made of numerical results based on two methods. Our work provides nonperturbative and quantitative methods to evaluate the particle production for the inflationary cosmology.