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<title>Xu Cheng — Neckpinch</title><link>https://neckpinch.com/authors/xu-cheng/</link><description>New arXiv papers by Xu Cheng, from Neckpinch</description>
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<item><title>Eigenvalue Estimates for Schrödinger Operators on Ricci Shrinkers</title><link>https://neckpinch.com/papers/2605.23199/</link><guid isPermaLink="false">arxiv:2605.23199</guid><pubDate>Fri, 22 May 2026 00:00:00 GMT</pubDate><description>Xu Cheng, Franciele Conrado, Neilha Pinheiro, Detang Zhou — Let (M, g, f, τ) be a complete Ricci shrinker satisfying Ric+∇²f=g/2τ and let R denote its scalar curvature. For a confined function V on M, we obtain a lower bound for the lowest eigenvalue of the Schrödinger operator −Δ+R/4+V, expressed in terms of an integral quantity involving V and the shrinker entropy, and the equality case is characterized by the potential functions. We further generalize this estimate to complete Riemannian manifolds via Perelman&apos;s μ-functional. We also study the drifted Schrödinger operator −Δ_f+V on smooth metric measure spaces. In particular, on Ricci shrinkers, we derive a lower bound for its lowest eigenvalue, with equality if and only if V is affine.</description><category>Ricci solitons</category><category>Scalar curvature</category><category>Limit spaces &amp; RCD</category><category>Eigenvalues &amp; spectrum</category></item>
<item><title>On Euler characteristic and Hitchin-Thorpe inequality for four-dimensional compact Ricci solitons</title><link>https://neckpinch.com/papers/2203.14916/</link><guid isPermaLink="false">arxiv:2203.14916</guid><pubDate>Mon, 28 Mar 2022 00:00:00 GMT</pubDate><description>Xu Cheng, Ernani Ribeiro, Detang Zhou — In this article, we investigate the geometry of 4-dimensional compact gradient Ricci solitons. We prove that, under an upper bound condition on the range of the potential function, a 4-dimensional compact gradient Ricci soliton must satisfy the classical Hitchin-Thorpe inequality. In addition, some volume estimates are also obtained.</description><category>Ricci solitons</category><category>4-manifolds</category></item>
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