Emission of pairs of Minkowski photons through the lens of the Unruh effect

Abstract

We discuss the emission of pairs of photons by charges with generic worldlines in the Minkowski vacuum from the viewpoint of inertial observers and interpret them from the perspective of Rindler observers. We show that the emission of pairs of Minkowski photons corresponds, in general, to three distinct processes according to Rindler observers: scattering, and emission and absorption of pairs of Rindler photons. In the special case of uniformly accelerated charges, the radiation observed in the inertial frame can be fully described by the scattering channel in the Rindler frame. Therefore, the emission of pairs of Minkowski photons -- commonly referred to as Unruh radiation -- can be seen as further evidence supporting the Unruh effect.