Gravitational self-force and conservative effects: a testing ground for theories of gravity

Abstract

Considering extreme-mass-ratio inspirals along with the conservative dynamics of gravitational self-force, we compare viable theories of gravity. In particular, by examining a Schwarzschild background we analyse the self-force-induced corrections to gauge-invariant benchmarks given by the orbital frequency at the ISCO and the spin-precession rate. Moreover, following an established indication of modifications to the equations of motion in extended theories of gravity, we exploit a phenomenological approach, relying on the variability of the gravitational constant G, to incorporate these modifications. We find that conservative effects shape up to be a test-bed for theories of gravity, allowing us to contrast General Relativity with competing theories. By examining strong-field constraints, we highlight a wide margin of investigation in the context of LISA Mission.