**Shock generation** is a leading topic in nonlinear physics and optics. Shock waves occur whenever one enters highly nonlinear regimes either in time or in space. The origin of the ** undular bores** is among the mysterious dynamics of shock wave generation. The undular bores are the fast oscillations that regularize the wave-breaking after the shock; their features are very difficult to understand theoretically.

A typical phenomenon is the appearance of the ** Batman ears** in the optical intensity when the shock occurs; these “ears” are very pronounced peaks limiting the region of the shock and including undulars bores. Figures above show the Batman ears in the far field of a shock wave genereated in the spatial nonlinear optical propagation. Beyond numerical simulations, we do not have a complete theoretical description of this effect.

In a paper published in Optics Express (arXiv:1601.05796)Maria Chiara Braidotti, Silvia Gentilini, and Claudio Conti show that Gamow vectors of the reversed harmonic oscillator provide a new theoretical tool for the quantitative description of spatial shock waves in nonlocal media. The analytical calculations perfectly reproduce our experiments. This opens a number of possibilities for describing and controlling the shock waves in highly nonlocal and non-instantaneous media. The results also show the validity of the novel theoretical methods inherited by the so-called “time-asymmetric quantum-mechanics.”

The picture above shows the comparison between experiments and the analytically calculated Gamow vectors.