“…Dispersive shock waves (DSWs) appear when dispersion dominates dissipation for step-like data; they have been seen in plasmas [1], fluids (e.g., undular bores) [2,3], superfluids [4,5,6,7], and optics [8,9,10,11]. The Korteweg-de Vries (KdV) equation is the leading-order asymptotic equation for weakly dispersive and weakly nonlinear systems [12].…”