Infrared Divergences and Quantum Coherence

Understand

In theories with long-range forces like QED or perturbative gravity, only rates that include emitted soft radiation are non-vanishing.

• Independently of detector resolution, finite observables can only be obtained after integrating over the IR-component of this radiation.
• This integration can lead to some loss of quantum coherence.
• In this note, however, we argue that it should in general not lead to full decoherence.