Next-to-leading order spin-orbit effects in the equations of motion, energy loss and phase evolution of binaries of compact bodies in the effective field theory approach

TL;DR

This paper calculates next-to-leading order spin-orbit effects on the equations of motion, energy loss, and phase evolution of binary compact objects using the effective field theory approach, aiding gravitational wave modeling.

Contribution

It provides the first comprehensive EFT-based calculation of spin-orbit effects at next-to-leading order for binary systems, including energy, motion, and phase evolution.

Findings

Derived spin-orbit corrections to equations of motion and energy loss.

Computed orbital frequency and phase evolution including spin effects.

Confirmed equivalence with other formalisms.

Abstract

We compute spin-orbit effects in the equations of motion, binding energy and energy loss of binary systems of compact objects at the next-to-leading order in the post-Newtonian (PN) approximation in the effective field theory (EFT) framework. We then use these quantities to compute the evolution of the orbital frequency and accumulated orbital phase including spin-orbit effects beyond the dominant order. To obtain the results presented in this paper, we make use of known ingredients in the EFT literature, such as the potential and the multipole moments with spin effects at next-to-leading order, and which are given in the linearized harmonic gauge and with the spins in the locally flat frame. We also obtain the correction to the center-of-mass frame caused by spin-orbit effects at next-to-leading order. We demonstrate the equivalence between our EFT results and those which were obtained elsewhere using different formalisms. The results presented in this paper provide us with the final ingredients for the construction of theoretical templates for gravitational waves including next-to-leading order spin-orbit effects, which will be presented in a future publication.