Dressed infrared quantum information

Understand

We study information-theoretic aspects of the infrared sector of quantum electrodynamics, using the dressed-state approach pioneered by Chung, Kibble, Faddeev-Kulish and others.

• In this formalism QED has an IR-finite S-matrix describing the scattering of electrons dressed by coherent states of photons.
• We show that measurements sensitive only to the outgoing electronic degrees of freedom will experience decoherence in the electron momentum basis due to unobservable photons in the dressing.
• We make some comments on possible refinements of the dressed-state formalism, and how these considerations relate to the black hole information paradox.