Rigidity and non-existence results for collapsed translators
Debora Impera, Niels Martin Møller, Michele Rimoldi
TL;DR
The article addresses the problem of characterizing collapsed self-translating solitons in $\mathbb{R}^3$ with finite entropy. It introduces a weighted parabolic framework using the drift Laplacian $L=\Delta-e_3\cdot\nabla$ and a universal $L$-superharmonic function to prove a sharp rigidity result: among slab-confined translators of width $\pi$, the grim reaper cylinder is the unique surface that is bounded from below. The authors also derive nonexistence results for slab widths $\omega<\pi$ and for certain slanted halfspaces when $\omega=\pi$, and show a boundary-preserving rigidity to vertical planes under prescribed boundary data. Overall, the work provides a direct, parabolicity-based approach to rigidity and nonexistence results for collapsed translators, complementing existing mean-convex classifications and highlighting the role of finite entropy and the Ilmanen conformal metric in translating solitons.
Abstract
We prove a rigidity result for mean curvature self-translating solitons, characterizing the grim reaper cylinder as the only finite entropy self-translating 2-surface in $\mathbb{R}^3$ of width $π$ and bounded from below. The proof makes use of parabolicity in a weighted setting applied to a suitable universally $L$-superharmonic function defined on translaters in such slabs.
