We adopt the Dirac–Detweiler–Whiting radiative and regular effective field in curved spacetime. Thereby, we derive straightforwardly the first order perturbative correction to the geodesic of the background in a covariant form, for the extreme mass ratio two-body problem. The correction contains the self-force contribution and a background metric-dependent term.
Regularization of fields for self-force problems in curved spacetime: Foundations and a time-domain application