First Detection of the Acoustic Oscillation Phase Shift Expected from the Cosmic Neutrino Background

Follin, Brent; Knox, Lloyd; Millea, Marius; Pan, Zhen

United States

Abstract

The unimpeded relativistic propagation of cosmological neutrinos prior to recombination of the baryon-photon plasma alters gravitational potentials and therefore the details of the time-dependent gravitational driving of acoustic oscillations. We report here a first detection of the resulting shifts in the temporal phase of the oscillations, which we infer from their signature in the cosmic microwave background temperature power spectrum.

2015 Physical Review Letters
Planck 140