Lorenz gauge in linearized gravity
= Lorenz gauge in linearized gravity
{c}
The Lorenz condition $\partial^\mu\bar h_{\mu\nu}=0$ reduces the vacuum field equation to $\Box\bar h_{\mu\nu}=0$. A plane-wave amplitude therefore satisfies $k^\mu H_{\mu\nu}=0$ and $k^\mu k_\mu=0$.