Next-order spin–orbit contributions to chaos in compact binaries

Abstract

This paper is mainly devoted to numerically investigating the effects of the next-order spin–orbit interactions including the 2.5 post-Newtonian order term of the equations of motion and the second post-Newtonian order terms of the spin precession equations on chaos in the conservative Lagrangian dynamics of a spinning compact binary system. It is shown sufficiently through individual orbit simulations, the dependence of the invariant fast Lyapunov indicators on the variations of initial spin angles and the phase space scans for chaos, that the next-order spin–orbit contributions do play an important role in the amplification of chaos.