The orbital stability of the solitary wave solutions of the generalized Camassa-Holm equation

In this paper, we consider the orbital stability of smooth solitary wave solutions of the generalized Camassa-Holm equation. By constructing the functional extremum problem and using the orbital stability theory presented by Grillakis, Shatah, Strauss and Bona, and Souganidis, we show that the solitary wave solutions of the generalized Camassa-Holm equation are orbitally stable or unstable as determined by the sign of a discriminant. The conclusions presented by the previous authors, such as Hakkaev and Kirchev, Constantin and Strauss, can be considered as a special case of our results.