Comparison Theorems for the Profile Curve Equation of Rotationally Symmetric Self-Shrinkers
Abstract
Mean curvature flow is a fundamental geometric evolution equation in which a submanifold moves in the normal direction with velocity equal to its mean curvature vector. Self-shrinkers arise naturally as self-similar solutions to the mean curvature flow and play an important role as models for finite-time singularities. Among nontrivial examples of compact embedded self-shrinkers, the rotationally symmetric self-shrinking torus constructed by Angenent is one of the most important. However, the uniqueness of the Angenent torus remains a major open problem. In this paper, we study rotationally symmetric self-shrinkers of type π1Γ πnβ1 from the point of view of ordinary differential equations. We analyze the profile curves of rotationally symmetric self-shrinkers, focusing on the behavior of their vertical points and the curves traced out by these points as the initial height varies. We give a new proof of the existence of the Angenent torus by showing that two families of vertical-point trajectories must intersect. We further derive the linearized equation associated with the rotationally symmetric self-shrinker equation and apply a Sturm-type comparison theorem to obtain sufficient conditions for the monotonicity of horizontal-point trajectories. In particular, we prove a comparison theorem for solutions near the spherical self-shrinker x2+r2=2n, and establish partial monotonicity results for the curves of horizontal points. These results provide a possible approach to the uniqueness problem for the Angenent torus.
Related
- Rigidity theorems of complete self-shrinkers in the Euclidean space
- On Rotationally Symmetric Norms
- Seifert type magnetohydrostatic equilibria in rotationally symmetric toroidal domains
- Almgren frequency and Agmon convexity on rotationally symmetric Cartan-Hadamard manifolds
- On convex bodies with rotationally symmetric planar projections
BibTeX
@misc{peng2026comparison,
title = {{Comparison Theorems for the Profile Curve Equation of Rotationally Symmetric Self-Shrinkers}},
author = {Peng Peng},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2606.20276},
eprint = {2606.20276},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.20276},
}
RIS
TY - UNPB
TI - Comparison Theorems for the Profile Curve Equation of Rotationally Symmetric Self-Shrinkers
AU - Peng Peng
PY - 2026
DA - 2026/09/03
PB - arXiv
DO - 10.48550/arxiv.2606.20276
UR - https://arxiv.org/abs/2606.20276
AB - Mean curvature flow is a fundamental geometric evolution equation in which a submanifold moves in the normal direction with velocity equal to its mean curvature vector. Self-shrinkers arise naturally as self-similar solutions to the mean curvature flow and play an important role as models for finite-time singularities. Among nontrivial examples of compact embedded self-shrinkers, the rotationally symmetric self-shrinking torus constructed by Angenent is one of the most important. However, the uniqueness of the Angenent torus remains a major open problem. In this paper, we study rotationally symmetric self-shrinkers of type π^1Γ π^nβ1 from the point of view of ordinary differential equations. We analyze the profile curves of rotationally symmetric self-shrinkers, focusing on the behavior of their vertical points and the curves traced out by these points as the initial height varies. We give a new proof of the existence of the Angenent torus by showing that two families of vertical-point trajectories must intersect. We further derive the linearized equation associated with the rotationally symmetric self-shrinker equation and apply a Sturm-type comparison theorem to obtain sufficient conditions for the monotonicity of horizontal-point trajectories. In particular, we prove a comparison theorem for solutions near the spherical self-shrinker x^2+r^2=2n, and establish partial monotonicity results for the curves of horizontal points. These results provide a possible approach to the uniqueness problem for the Angenent torus.
ER -