Kyeongho Bang — Neckpinchhttps://neckpinch.com/authors/kyeongho-bang/New arXiv papers by Kyeongho Bang, from Neckpinch Tue, 03 Nov 2026 08:41:12 GMT Uniqueness of positively curved ancient Ricci flows on surfaces with boundaryhttps://neckpinch.com/papers/2608.26619/arxiv:2608.26619Thu, 27 Aug 2026 00:00:00 GMTKyeongho Bang, Eric Chen, Wenkui Du — We establish the existence and uniqueness modulo time-independent diffeomorphisms of the positively curved ancient Ricci flow (M², ∂M², g(t)) on a two-dimensional surface with boundary, assuming uniformly bounded diameter and constant positive boundary geodesic curvature. In particular, this ancient Ricci flow is rotationally symmetric, its backward limit is the flat disk, and its forward limit is a half-spherical singularity. To our knowledge, this result is the first instance of a classification result for ancient Ricci flows with boundary.Ricci flowAncient solutionsSingularitiesSurfacesStability & uniquenessRotational symmetry & warped products