Scaler radiation emitted from a source rotating around a black hole

We analyse the scalar radiation emitted from a source rotating around a Sch warzschild black hole using the framework of quantum held theory at the tre e level. We show that for relativistic circular orbits the emitted power is about 20-30% smaller than what would be obtained in Minkowski spacetime. W e also show that most of the emitted energy escapes to infinity. Our formal ism can readily be adapted to investigate similar processes.