Fermi-Walker transport
= Fermi-Walker transport
{c}
{title2=$Ds^\mu/d\tau=(u^\mu a_\nu-a^\mu u_\nu)s^\nu/c^2$}
Transport defining a nonrotating frame along an accelerated <timelike curve>. With <four-velocity> normalization $u^\mu u_\mu=-c^2$ and <four-acceleration> $a^\mu=Du^\mu/d\tau$, the displayed equation preserves inner products and keeps a spatial spin orthogonal to $u$. Along a <geodesic>, $a^\mu=0$ and it reduces to <parallel transport>.