One-Parametric Family of the Double-Scaling Limits in the Hermitian Matrix Model Φ⁶: Onset of Nondissipative Shock Waves

We construct a one-parametric family of the double-scaling limits in the hermitian matrix model $\Phi^6$ for 2D quantum gravity. The known limit of Bresin, Marinari and Parisi belongs to this family. The family is represented by the Gurevich-Pitaevskii solution of the Korteveg-de Vries equation which describes the onset of nondissipative shock waves in media with small dispersion. Numerical simulation of the universal Gurevich-Pitaevskii solution is made.