Persistence properties of a Camassa–Holm type equation with ( n + 1)-order non-linearities

Abstract

Lower order conservation laws and symmetries of a family of hyperbolic equations having the Camassa–Holm equation as a particular member are obtained. We show that the equation has two conservation laws with zeroth order characteristics and that its symmetries are generated by translations in the independent variables and a certain scaling, as well as some invariant solutions are studied. Next, we consider persistence and asymptotic properties for the solutions of the equation considered. In particular, we analyze the behavior of the solutions of the equation for large values of the spatial variable. We show that if the initial data has a certain asymptotic exponential decaying, then such a property persists for any time as long as the solution exists. Moreover, depending on the behavior of the initial data for large values of the spatial variable and if for some further time the solution shares the same behavior, then it necessarily vanishes identically. Finally, we prove unique continuation results for the solutions of the equation.