Effects of space-time noncommutativity on the angular power spectrum of the CMB

TL;DR

This paper explores how space-time noncommutativity in the early universe affects quantum fluctuations during inflation, leading to a damping in the CMB angular power spectrum at large scales.

Contribution

It introduces a model linking space-time noncommutativity to observable CMB features, specifically the damping of low-l modes, which is a novel approach.

Findings

Damping of the angular power spectrum at low multipoles.

Connection between noncommutative geometry and CMB anisotropies.

Potential observational signatures of early universe noncommutativity.

Abstract

We investigate an inflationary model of the universe based on the assumption that space-time is noncommutative in the very early universe. We analyze the effects of space-time noncommutativity on the quantum fluctuations of an inflaton field and investigate their contributions to the cosmic microwave background (CMB). We show that the angular power spectrum l(l+1)C_l generically has a sharp damping for lower l if we assume that the last scattering surface is traced back to fuzzy spheres at the times when large-scale modes cross the Hubble horizon.