The Plateau–Rayleigh Instability of Translating \(\lambda \)-Solitons

Given a unit vector \({\textbf {v}}\in {\mathbb {R}}^3\) $\mathbf{v}\in {\mathbb{R}}^3$ and \(\lambda \in {\mathbb {R}}\) $\lambda \in \mathbb{R}$ , a translating \(\lambda \) $\lambda$ -soliton is a surface in \({\mathbb {R}}^3\) ${\mathbb{R}}^3$ whose mean curvature H satisfies \(H=\langle N,{\textbf {v}}\rangle +\lambda \) $H=⟨N,\mathbf{v}⟩+\lambda$ , where N is the Gauss map of the surface. In this paper, we extend the phenomenon of instability of Plateau–Rayleigh for translating \(\lambda \) $\lambda$ -solitons of cylindrical type, proving that long pieces of these surfaces are unstable. Specifically, we will provide explicit bounds on the length of these unstable surfaces in terms of \(\lambda \) $\lambda$ and the amplitude of the generating curve. It will be also proved that a graphical translating \(\lambda \) $\lambda$ -soliton is a minimizer of the weighted area in a suitable class of surfaces with the same boundary and the same weighted volume.