Paper · Dec 21, 2021

Hamilton-Ivey estimates for gradient Ricci solitons

Pak-Yeung Chan, Zilu Ma, Yongjia Zhang

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Abstract

We first show that any -dimensional non-Ricci-flat steady gradient Ricci soliton singularity model must satisfy for some positive constant . Then, we apply the Hamilton-Ivey estimate to prove a quantitative lower bound of the curvature operator for -dimensional steady gradient solitons with linear scalar curvatrue decay and proper potential function. The technique is also used to establish a sufficient condition for a -dimensional expanding gradient Ricci soliton to have positive curvature. This sufficient condition is satisfied by a large class of conical expanders. As an application, we remove the positive curvature condition in a classification result by Chodosh 14 in dimension three and show that any -dimensional gradient Ricci expander asymptotic to is rotationally symmetric, where is a constant and is the standard metric on with constant curvature .

Comments: 34 pages

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The 8 papers on this site closest to this one, judged by the topics they share, the words and phrases in their titles and abstracts, and their authors. They are not its citations, but a map of the work around it. Papers here go back to 2021, plus the canon.

Connected papers This paper in the centre and the 8 papers closest to it around it, in date order clockwise from the top. The closer a paper sits to the centre, the stronger the connection. This paper On a dichotomy of the curvature decay of steady Ricci soliton (Pak-Yeung Chan and Bo Zhu, 2021)3Chan 2021 An optimal volume growth estimate for noncollapsed steady gradient Ricci solitons (Richard H. Bamler, Pak-Yeung Chan, Zilu Ma et al., 2021)5Bamler 2021 Volume growth estimates of gradient Ricci solitons (Pak-Yeung Chan, Zilu Ma and Yongjia Zhang, 2022)2Chan 2022 Lower bounds for the scalar curvatures of Ricci flow singularity models (Pak-Yeung Chan, Bennett Chow, Zilu Ma et al., 2022)1Chan 2022 Dimension Reduction for Positively Curved Steady Solitons (Pak-Yeung Chan, Zilu Ma and Yongjia Zhang, 2023)6Chan 2023 On noncollapsed F-limit metric solitons (Pak-Yeung Chan, Zilu Ma and Yongjia Zhang, 2024)7Chan 2024 Curvature pinching of asymptotically conical gradient expanding Ricci solitons (Huai-Dong Cao and Junming Xie, 2025)4Cao 2025 Curvature estimates for steady and expanding solitons in higher dimensions (Pak-Yeung Chan and Ming Hsiao, 2025)8Chan 2025
Closer to the centre: more closely connected. Clockwise from the top: oldest to newest. Ricci flowWider flowsalso connected to each other
  1. Lower bounds for the scalar curvatures of Ricci flow singularity models

    Pak-Yeung Chan, Bennett Chow, Zilu Ma et al. PDF

    Topics Ricci-flat & Calabi–Yau, Singularities, Ricci solitons · Same authors Pak-Yeung Chan, Zilu Ma, Yongjia Zhang · Shared terms “singularity models”, “flat steady”, “lower bound”

  2. Volume growth estimates of gradient Ricci solitons

    Pak-Yeung Chan, Zilu Ma and Yongjia Zhang PDF

    Topics Ricci solitons · Same authors Pak-Yeung Chan, Zilu Ma, Yongjia Zhang · Shared terms “gradient Ricci”, “expanding gradient”

  3. On a dichotomy of the curvature decay of steady Ricci soliton

    Pak-Yeung Chan and Bo Zhu PDF

    Topics Ricci-flat & Calabi–Yau, Ricci solitons · Same author Pak-Yeung Chan · Shared terms “flat steady”, “proper potential”, “steady gradient”

  4. Curvature pinching of asymptotically conical gradient expanding Ricci solitons

    Huai-Dong Cao and Junming Xie PDF

    Topics Curvature pinching, 3-manifolds, Ricci solitons · Shared terms “Hamilton Ivey”, “Ricci expander”, “dimensional gradient”

  5. An optimal volume growth estimate for noncollapsed steady gradient Ricci solitons

    Richard H. Bamler, Pak-Yeung Chan, Zilu Ma et al. PDF

    Topics Ricci solitons · Same authors Pak-Yeung Chan, Zilu Ma, Yongjia Zhang · Shared terms “steady gradient”, “gradient Ricci”

  6. Dimension Reduction for Positively Curved Steady Solitons

    Pak-Yeung Chan, Zilu Ma and Yongjia Zhang PDF

    Topics Singularities, Ricci solitons · Same authors Pak-Yeung Chan, Zilu Ma, Yongjia Zhang · Shared terms “steady gradient”, “gradient Ricci”

  7. On noncollapsed -limit metric solitons

    Pak-Yeung Chan, Zilu Ma and Yongjia Zhang PDF

    Topics Singularities, Ricci solitons · Same authors Pak-Yeung Chan, Zilu Ma, Yongjia Zhang · Shared terms “singularity models”, “lower bound”

  8. Curvature estimates for steady and expanding solitons in higher dimensions

    Pak-Yeung Chan and Ming Hsiao PDF

    Topics Ricci solitons · Same author Pak-Yeung Chan · Shared terms “proper potential”, “curvature operator”, “Ricci expander”

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Background reading

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In the guidebook

  1. 12B.6
    Bounded Curvature at Bounded DistanceBook 12B · κ-Solutions and Surgery

    The heart of the canonical neighbourhood proof: why curvature at bounded rescaled distance from a point of high curvature stays bounded, via incomplete limits, cones and Hamilton–Ivey pinching (Morgan–Tian, chapter 10).

  2. 6A.9
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    Critical patch size, travelling fronts and their speeds, bistable waves and the Allen–Cahn equation, Turing patterns, and the curvature of a Ricci flow as a reaction–diffusion system.

  3. 11A.7
    Maximum Principles under Ricci FlowBook 11A · The Ricci Flow: Existence and Maximum Principles

    Scalar and tensor maximum principles, and preserved curvature conditions.