journal club on aspects of information, quantum theory, and gravity
03 Jun 2025
Levy Bruno do Nascimento Batista
Recently, Wald and collaborators have proposed a novel source of decoherence of charges and masses in a spatial superposition state when placed in a spacetime with Killing horizons. They argued that the effect is primarily caused by the emission of soft particles through these horizons, which will eventually happen even if the process is assumed to be adiabatic. We investigate this claim in a rather different setting, with a gapless detector interacting with a massive scalar field. We introduce how such interaction is described and how to quantify the resulting decoherence. Then, we investigate our proposed model in two seminal cases: when the components of the spatial superposition are inertial and when they are uniformly accelerated in Minkowski space. Working in an analogous regime, we compare our results to those obtained by Wald, highlighting their similarities. Finally, we discuss what we sought to improve with our model and how it might clarify some questions left open in the original work.