Parametric solutions of the generalized short pulse equations

We consider three novel PDEs associated with the integrable generalizations of the short pulse (SP) equation classified recently by Hone et al (2018 Lett. Math. Phys. 108 927-47). In particular, we obtain a variety of exact solutions by means of a direct method analogous to that used for solving the SP equation. The main results reported here are the parametric representations of the multisoliton solutions. These solutions include cusp solitons, unbounded solutions with finite slope and breathers. In addition, the cusped periodic wave solutions are constructed from the cusp solitons by means of a simple procedure. As for non-periodic solutions, smooth breather solutions are of particular interest from the perspective of applications to real physical phenomena. The cycloid reduced from the periodic traveling wave with cusps is also worth remarking in connection with Gerstner's trochoidal solution in deep gravity waves. A number of works are left for future study, some of which will be addressed in concluding remarks.