Synchrotron scalar radiation from a source in ultrarelativistic circular orbits around a Schwarzschild black hole

Gravitational waves emitted by a particle rotating around a Schwarzschild black hole: A semiclassical approach

“…We found that high multipoles of the gravitational radiation are significantly enhanced only for unstable orbits, although the low multipole modes remain as a relevant contribution to the emitted power even in this case. We also have found that no high frequency peaks are present in the power spectrum, unlike the scalarradiation case [25]. We note that the particle in a stable orbit will emit radiation, gradually losing energy and inspiraling to orbits with smaller radii.…”

Scalar radiation from a source rotating around a regular black hole

“…Positive-frequency solutions to Eq. (16), with respect to the timelike Killing vector field ∂ t , can be written as…”

“…Using the quantum field theory in curved spacetimes framework, the scalar radiation emission in Schwarzschild spacetime was revisited in Refs. [14][15][16][17]. In the context of geodesic synchrotron radiation, this framework has been used to analyze the emission of gravitational radiation in Ref.…”

Corrigendum: Scalar radiation emitted from a source rotating around a black hole (2000 Class. Quantum Grav. 17 19)

“…Therefore, equations ( The subsequent low-energy approximation for W S,obs needs to be corrected accordingly. We also note that similar corrections need to be made in [1][2][3][4][5][6], which used equations similar to (35) and (36) for estimating the portion of the radiation emitted to infinity.…”