Possible Evidence for Planck-Scale Resonant Particle Production during Inflation from the CMB Power Spectrum

TL;DR

This paper suggests that a dip in the CMB power spectrum could be due to resonant production of supermassive particles during inflation, hinting at new physics at the Planck scale.

Contribution

It proposes a novel interpretation of CMB features as evidence for Planck-scale particle creation during inflation.

Findings

A dip in the CMB power spectrum at l=10-30 can be modeled by resonant particle creation.

The best-fit model indicates creation of fermions with mass ~15 times the Planck mass.

The coupling constant between inflaton and fermions is near unity.

Abstract

The power spectrum of the cosmic microwave background from both the Planck and WMAP data exhibits a slight dip in for multipoles in the range of l=10-30. We show that such a dip could be the result of resonant creation of a massive particle that couples to the inflaton field. For our best-fit models, epochs of resonant particle creation reenters the horizon at wave numbers of k* ~ 0.00011 (h/Mpc). The amplitude and location of these features correspond to the creation of a number of degenerate fermion species of mass ~ 15 times the planck mass during inflation with a coupling constant between the inflaton field and the created fermion species of near unity. Although the evidence is marginal, if this interpretation is correct, this could be one of the first observational hints of new physics at the Planck scale.