A novel approach to the equivalence principle paradox - Does gravity make a charged body radiate?

The longstanding question of whether an electrically charged particle emits electromagnetic radiation when accelerated by a gravitational field has led to what is often called the equivalence principle paradox. While it is commonly assumed that the answer must be binary—either radiation occurs in accordance with the Larmor formula or there is no radiation at all—we show that a more nuanced view is advisable. By analyzing the energy and momentum exchange between a charged body and its associated electromagnetic field in both homogeneous and inhomogeneous gravitational fields, we show that radiation is not an all-or-nothing phenomenon. The Larmor formula gives the upper bound of the radiated energy flux, which is realized only when the body alone receives the full energy-momentum input. In a perfectly homogeneous gravitational field, both the body and its electromagnetic field are in free fall and the radiation disappears completely. If the gravitational field is not homogeneous, energy and momentum transports take place within the electromagnetic field due to the tidal effect. The stronger these are, the more radiation is emitted. Our conclusions are extended from point charges to arbitrary rigid configurations of charged or magnetized bodies. ... mehrOur analysis relies only on classical field theory, Einstein’s mass-energy equivalence, and basic properties of tidal forces, offering a conceptually clear resolution of the paradox.