Statistics of Anisotropies in Inflation with Spectator Vector Fields

Understand

We study the statistics of the primordial power spectrum in models where massless gauge vectors are coupled to the inflaton, paying special attention to observational implications of having fundamental or effective horizons embedded in a bath of infrared fluctuations.

• As quantum infrared modes cross the horizon, they classicalize and build a background vector field.
• We find that the vector experiences a statistical precession phenomenon.
• Implications for primordial correlators and the interpretation thereof are considered.