Ancient Gauss Curvature Flows of Bounded Width
Beomjun Choi, Kyeongsu Choi, Dongjun Noh
TL;DR
This work develops ancient, non-self-similar solutions for curvature-driven flows in 3D: a pancake with flat sides under the Gauss curvature flow and sausage-type ancient solutions for the α-GCF with α>1/2. The authors establish a viscosity-solution framework, derive curvature-ratio evolution on rotationally symmetric profiles, and prove axisial minimality of curvature to enable barrier constructions. They construct the pancake via width-bounded approximations converging to a $C^{1,1}$ ancient solution, and obtain sausage solutions by both small-α barrier methods and large-α translator gluing, ensuring cylinder-like asymptotics and eventual extinction to a round point. These results illuminate flat-side persistence, width control, and asymptotic structures of ancient convex flows, contributing to the classification and behavior of non-self-similar ancient solutions in low dimensions.
Abstract
In this paper, we construct a pancake-like ancient compact solution with flat sides to the Gauss curvature flow, contained in a slab. Also, we construct sausage-like ancient compact solutions to the $α$-Gauss curvature flow with $α>\frac{1}{2}$, asymptotic to a round cylinder.
