On scalar radiation

Understand

We discuss radiation in theories with scalar fields.

• Our key observation is that even in flat spacetime, the radiative fields depend qualitatively on the coupling of the scalar field to the Ricci scalar: for non-minimally coupled scalars, the radiative energy density is not positive definite, the radiated power is not Lorentz invariant and it depends on the derivative of the acceleration.
• We explore implications of this observation for radiation in conformal field theories.
• First, we find a relation between two coefficients that characterize radiation, that holds in all the conformal field theories we consider.