Surface response to a localized impulsive velocity (source code)

= Surface response to a localized impulsive velocity

If an initially flat one-dimensional surface receives velocity $-W$ on $|x|<\epsilon$ and zero velocity elsewhere, its linear capillary-wave response is
$$
\eta(x,t)=-\frac{2W}{\pi S}
\int_0^\infty
\frac{\sin(k\epsilon)\sin(Sk^{3/2}t)\cos(kx)}{k^{5/2}}\,dk.
$$