Planck scale effects and the suppression of power on the large scales in the primordial spectrum

TL;DR

This paper investigates how Planck scale physics could modify the primordial power spectrum during inflation, potentially explaining the observed suppression of large-scale power in the CMB anisotropies.

Contribution

It introduces a Lorentz-invariant model of Planck scale effects that reproduces standard spectra on small scales but suppresses power on large scales, aligning with CMB observations.

Findings

Standard spectrum on small scales

Suppression of large-scale power

Potential explanation for CMB low multipole deficit

Abstract

The enormous red-shifting of the modes during the inflationary epoch suggests that physics at the very high energy scales may modify the primordial perturbation spectrum. Therefore, the measurements of the anisotropies in the Cosmic Microwave Background (CMB) could provide us with clues to understanding physics beyond the Planck scale. In this proceeding, we study the Planck scale effects on the primordial spectrum in the power-law inflation using a model which preserves local Lorentz invariance. While our model reproduces the standard spectrum on small scales, it naturally predicts a suppression of power on the large scales -- a feature that seems to be necessary to explain deficit of power in the lower multipoles of the CMB.