Stability of compacton solutions of Fifth-order nonlinear dispersive equations

Abstract

We consider fifth-order nonlinear dispersive K(m,n,p) type equations to study the effect of nonlinear dispersion. Using simple scaling arguments we show, how, instead of the conventional solitary waves such as solitons, the interaction of the nonlinear dispersion with nonlinear convection generates compactons-the compact solitary waves free of exponential tails. This interaction also generates many other solitary wave structures such as cuspons, peakons, tipons etc which are otherwise unattainable with linear dispersion. Various self-similar solutions of these higher-order nonlinear dispersive equations are also obtained using similarity transformations. Further, it is shown that, like the third-order nonlinear K(m,n) equations, the fifth-order nonlinear dispersive equations also have the same four conserved quantities and, furthermore even any arbitrary odd-order nonlinear dispersive K(m,n,p,...) type equations also have the same three (and most likely the four) conserved quantities. Finally, the stability of the compacton solutions for the fifth-order nonlinear dispersive equations are studied using linear stability analysis. From the results of the linear stability analysis it follows that, unlike solitons, all the allowed compacton solutions are stable, since the stability conditions are satisfied for arbitrary values of the nonlinear parameters.