Analytical solutions of bound timelike geodesic orbits in effective-one-body frame
Phys. Rev. D 112, 104012 – Published 7 November, 2025
DOI: https://doi.org/10.1103/7g4q-5crv
Abstract
We derive the approximate analytical solutions of the bound timelike geodesic orbits in the effective-one-body frame with an extreme-mass ratio limit. The analytical solutions are expressed in terms of the elliptic integrals using Mino time as the independent variable. Since Mino time decouples the and motion, we also give explicit expressions for three orbital frequencies using the Fourier series expansion. With these analytical expressions at hand, we can perform Fourier expansions in Mino time for any function expressed in terms of the coordinates . In particular, the observer’s time is decomposed into Mino time , and the frequency-domain description is constructed from the -Fourier expansion and the expansion of . These analytical expressions are quite simple to implement, and can be applicable for calculating gravitational waves from extreme mass-ratio inspirals with the frequency-domain Teukolsky equation.