Interaction of a wave with an accelerating object and the equivalence principle

A new look at the so-called effect of an accelerating matter is presented. It was previously stated that the effect is optical in nature and consists in changing the frequency of the wave passing through a refractive sample moving with acceleration. However, from a simple consideration based on the principle of equivalence, it follows that the idea of the connection of the effect only with the refraction phenomenon is unreasonably narrow, and a change in the wave frequency should inevitably occur during scattering by any object moving with acceleration. Such an object can be either an elementary scatterer or any device transmitting a narrowband signal.