Gravitational-wave inspiral time
= Gravitational-wave inspiral time
{title2=$t_{\rm merge}=5c^5A^4/(256G^3\mu M^2)$}
The leading circular, constant-mass <gravitational-wave inspiral time> follows by integrating the quadrupole radiation-reaction equation $\dot A=-64G^3\mu M^2/(5c^5A^3)$. It assumes initially weak gravity and neglects eccentricity, mass exchange and finite contact separation. It is $3/8$ of the associated instantaneous period-decay timescale.