Existence of Kink Waves and Periodic Waves for a Perturbed Defocusing mKdV Equation

The existence of kink waves and periodic waves for a perturbed defocusing mKdV equation is established by using geometric singular perturbation theory. In addition, by analyzing the perturbation of the Hamiltonian vector field with an elliptic Hamiltonian of degree four, a two saddle cycle is exhibited. It is proven that the wave speed c0(h)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$c_0(h)$$\end{document} is decreasing on h∈[-3/4,0]\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$h\in [-3/4,0]$$\end{document} by analyzing the ratio of Abelian integrals and the limit of wave speed is given. Furthermore, the relationship between the wave speed and the wavelength of traveling waves is obtained.