https://neckpinch.com/authors/gabjin-yun/New arXiv papers by Gabjin Yun, from Neckpinch Tue, 10 Nov 2026 04:10:28 GMT https://neckpinch.com/papers/1604.07018/arxiv:1604.07018Sun, 24 Apr 2016 00:00:00 GMTSeungsu Hwang, Gabjin Yun — In this paper, we prove rigidity results on gradient shrinking Ricci solitons with weakly harmonic Weyl curvature tensors. Let (Mⁿ, g) be a compact gradient shrinking Ricci soliton satisfying rm Ric_g + Ddf = ρg with ρ>0 constant. We show that if (M,g) satisfies δ𝓦 (·, ·, ∇f) = 0, then (M, g) is Einstein. Here 𝓦 denotes the Weyl curvature tensor. In the case of noncompact, if M is complete and satisfies the same condition, then M is rigid in the sense that M is given by a quotient of product of an Einstein manifold with Euclidean space. These are generalizations of the previous known results in, and.Ricci solitonsEinstein metricsStability & uniquenessBoundaries & non-compact https://neckpinch.com/papers/1604.04087/arxiv:1604.04087Thu, 14 Apr 2016 00:00:00 GMTGabjin Yun, Jinseok Co, Seungsu Hwang — On an n-dimensional complete manifold M, consider an h-almost gradient Ricci soliton, which is a generalization of a gradient Ricci soliton. We prove that if the manifold is Bach-flat and dh/du>0, then the manifold M is either Einstein or rigid. In particular, such a manifold has harmonic Weyl curvature. Moreover, if the dimension of M is four, the metric g is conformally flat.Ricci solitonsAlmost & η-Ricci solitonsBoundaries & non-compact