Abstract
Motivated by applications to the study of self-force effects in scalar-tensor theories of gravity, we calculate the self-force exerted on a scalar charge in a circular orbit about a Reissner-Nordström black hole. We obtain the self-force via a mode-sum calculation and find that our results differ from recent post-Newtonian calculations even in the slow-motion regime. We compute the radiative fluxes toward infinity and down the black hole and verify that they are balanced by energy dissipated through the local self-force—in contrast to the reported post-Newtonian results. The self-force and radiative fluxes depend solely on the black hole’s charge-to-mass ratio, the controlling parameter of the Reissner-Nordström geometry. They both monotonically decrease as the black hole approaches extremality. With respect to an extremality parameter , the energy flux through the event horizon is found to scale as as .
- Received 26 April 2018
DOI:https://doi.org/10.1103/PhysRevD.98.024024
© 2018 American Physical Society