Continuity for the rotation-two-component Camassa-Holm system

Abstract

This paper focuses on the Cauchy problem of the rotation-two-component Camassa-Holm(R2CH) system, which is a model of equatorial water waves that includes the effect of the Coriolis force. It has been shown that the R2CH system is well-posed in Sobolev spaces $ H^s(\mathbb{R})\times H^{s-1}(\mathbb{R}) $ with $ s>3/2 $. Using the method of approximate solutions in conjunction with well-posedness estimates, we further proved that the dependence on initial data is sharp, i.e., the data-to-solution map is continuous but not uniformly continuous. Moreover, we obtain that the solution map for the R2CH system is Hölder continuous in $ H^\theta(\mathbb{R})\times H^{\theta-1}(\mathbb{R}) $-topology for all $ 0\leq\theta<s $ with exponent $ \gamma $ depending on $ s $ and $ \theta $. The Coriolis term and higher nonlinear term in the R2CH system bring challenges to construct the counter-approximate solutions.