Airy displacement integral (source code)

= Airy displacement integral
{c}
{title2=$I_0(C),\ I_1(C)$}

For $q=e^{i\pi/6}$ define $I_0(C)=\int_0^\infty\operatorname{Ai}(q(s-C))ds$ and $I_1(C)=\int_0^\infty s\operatorname{Ai}(q(s-C))ds$. Both converge by <Airy function> decay. Integrating its differential equation gives $I_1-CI_0=iq\operatorname{Ai}\prime(-qC)$. These moments convert a decaying vorticity profile into its velocity and displacement for <three-layer long-wave shear-flow matching>.