Probing Planckian physics: resonant production of particles during inflation and features in the primordial power spectrum

TL;DR

This paper explores how resonant production of particles during inflation can create sharp features in the primordial power spectrum, potentially detectable through cosmic microwave background and large-scale structure observations, thus probing Planck-scale physics.

Contribution

It introduces the novel idea that particle production during inflation, not just after, can leave observable imprints in the primordial spectrum, linking inflationary physics to Planck-scale phenomena.

Findings

Resonant particle production during inflation modifies inflaton evolution.

Sharp features in the primordial power spectrum can result from this process.

Future observations could detect signatures of Planck-scale particles.

Abstract

The phenomenon of resonant production of particles {\it after} inflation has received much attention in the past few years. In a new application of resonant production of particles, we consider the effect of a resonance {\em during} inflation. We show that if the inflaton is coupled to a massive particle, resonant production of the particle during inflation modifies the evolution of the inflaton, and may leave an imprint in the form of sharp features in the primordial power spectrum. Precision measurements of microwave background anisotropies and large-scale structure surveys could be sensitive to the features, and probe the spectrum of particles as massive as the Planck scale.