  Clarifying the principles leading to complete decoherence is essential for
understanding information loss in black hole formation. We employ strictly
perturbative quantum master equations to compute the long-term decoherence rate
in infrared-divergent qubit dynamics. In moderately sub-Ohmic dissipation, we
find that this rate exceeds the Hubble's constant, meaning that infrared
particles do not completely destroy quantum information at the universe's
current age. Deep sub-Ohmic dissipation leads to infrared-divergent recovery of
quantum coherence.
