Testing quantum gravity effects with latest CMB observations

Abstract

Inspired by quantum gravitational physics, the approach of non-commutative (NC) phase space leads to a modified dispersion relation of gravitational waves. This feature, if applied to the very early universe, gives rise to a modified power spectrum of primordial tensor perturbations with a suppression of power on large scales. We confront this phenomenon with the BICEP2 and Planck experiments, and show that inflation with the modified dispersion relation can simultaneously fit the observations better than the standard inflationary paradigm. In particular, the numerical result implies that with the latest cosmological microwave background (CMB) observations, a quantum gravity modified power spectrum of primordial tensor modes is preferred at a statistical significance of more than $3\sigma$ compared with the minimal model. Our study indicates that the potential tension between the BICEP2 and Planck data may be resolved by quantum gravity effects.

5 pages, 2 figures, comments are welcome

References in corpus (2)

• Tensor Modes from a Primordial Hagedorn Phase of String Cosmology
• Probing Noncommutativity with Inflationary Gravitational Waves

Cited by in corpus (8)

• Measuring the speed of cosmological gravitational waves
• Effects of modified gravity on B-mode polarization
• Nonsingular bouncing cosmologies in light of BICEP2
• Inflation and Alternatives with Blue Tensor Spectra
• Single field inflation with modulated potential in light of the Planck and BICEP2
• Pre-inflationary genesis with CMB B-mode polarization
• Effect of transitions in the Planck mass during inflation on primordial power spectra
• Precision of future experiments measuring primordial tensor fluctuation