Paper · Jul 22, 2022

Rigidity of Lipschitz map using harmonic map heat flow

Man-Chun Lee, Luen-Fai Tam

PDF Abstract page

As on arXiv

Abstract

Motivated by the Lipschitz rigidity problem in scalar curvature geometry, we prove that if a closed smooth spin manifold admits a distance decreasing continuous map of non-zero degree to a sphere, then either the scalar curvature is strictly less than the sphere somewhere or the map is a distance isometry. Moreover, the property also holds for continuous metrics with scalar curvature lower bound in some weak sense. This extends a result in the recent work of Cecchini-Hanke-Schick and answers a question of Gromov. The method is based on studying the harmonic map heat flow coupled with the Ricci flow from rough initial data to reduce the case to smooth metrics and smooth maps so that results by Llarull can be applied.

Comments: 17 pages

Its neighbourhood

Connected papers

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 Short time existence for harmonic map heat flow with time-dependent metrics (Shaochuang Huang and Luen-Fai Tam, 2021)1Huang 2021 Gromov-Hausdorff stability of tori under Ricci and integral scalar curvature bounds (Shouhei Honda, Christian Ketterer, Ilaria Mondello et al., 2023)8Honda 2023 Rigidity of area non-increasing maps (Man-Chun Lee, Luen-Fai Tam and Jingbo Wan, 2023)4Lee 2023 Scalar curvature rigidity of the four-dimensional sphere (Simone Cecchini, Jinmin Wang, Zhizhang Xie et al., 2024)2Cecchini 2024 Ricci-DeTurck Flow from Initial Metric with Morrey-type Integrability Condition (Man-Chun Lee and Stephen Shang Yi Liu, 2024)3Lee 2024 Uniqueness of Ricci flow with scaling invariant estimates (Man-Chun Lee, 2025)5Lee 2025 Convergence of Ricci flow and long-time existence of Harmonic map heat flow (Kyeongsu Choi and Yi Lai, 2025)7Choi 2025 Mean curvature flow into an ambient Riemannian manifold evolving by Ricci flow coupled with harmonic map heat flow (José N. V. Gomes, Matheus Hudson and Carlos M. de Sousa, 2025)6Gomes 2025
Closer to the centre: more closely connected. Clockwise from the top: oldest to newest. Ricci flowWider flowsalso connected to each other
  1. Short time existence for harmonic map heat flow with time-dependent metrics

    Shaochuang Huang and Luen-Fai Tam PDF

    Topics Harmonic maps & DeTurck trick, Stability & uniqueness · Same author Luen-Fai Tam · Shared terms “map heat”, “heat flow”, “flow coupled”

  2. Scalar curvature rigidity of the four-dimensional sphere

    Simone Cecchini, Jinmin Wang, Zhizhang Xie et al. PDF

    Topics Harmonic maps & DeTurck trick, Scalar curvature, Stability & uniqueness · Shared terms “map heat”, “smooth map”, “zero degree”

  3. Ricci-DeTurck Flow from Initial Metric with Morrey-type Integrability Condition

    Man-Chun Lee and Stephen Shang Yi Liu PDF

    Topics Harmonic maps & DeTurck trick, Weak & singular flows, Scalar curvature · Same author Man-Chun Lee · Shared terms “curvature lower”, “lower bound”

  4. Rigidity of area non-increasing maps

    Man-Chun Lee, Luen-Fai Tam and Jingbo Wan PDF

    Topics Stability & uniqueness · Same authors Man-Chun Lee, Luen-Fai Tam · Shared terms “flow coupled”, “isometry”

  5. Uniqueness of Ricci flow with scaling invariant estimates

    Man-Chun Lee PDF

    Topics Harmonic maps & DeTurck trick, Stability & uniqueness · Same author Man-Chun Lee · Shared terms “map heat”, “heat flow”

  6. Mean curvature flow into an ambient Riemannian manifold evolving by Ricci flow coupled with harmonic map heat flow

    José N. V. Gomes, Matheus Hudson and Carlos M. de Sousa PDF

    Topics Harmonic maps & DeTurck trick · Shared terms “map heat”, “heat flow”, “flow coupled”

  7. Convergence of Ricci flow and long-time existence of Harmonic map heat flow

    Kyeongsu Choi and Yi Lai PDF

    Topics Harmonic maps & DeTurck trick, Stability & uniqueness · Shared terms “map heat”, “heat flow”

  8. Gromov-Hausdorff stability of tori under Ricci and integral scalar curvature bounds

    Shouhei Honda, Christian Ketterer, Ilaria Mondello et al. PDF

    Topics Harmonic maps & DeTurck trick, Scalar curvature, Stability & uniqueness · Shared terms “map heat”, “heat flow”, “Gromov”

Read around it

Background reading

The guides for the topics of this paper: what each idea is, why it matters, and the papers to read first.

In the guidebook

  1. 12C.9
    After PerelmanBook 12C · Extinction and the Proof

    Singular flows, the Smale conjecture, and Bamler’s theory.

  2. 6C.4
    The Yamabe Problem and Critical ExponentsBook 6C · Nonlinear PDE: Variational and Geometric Methods

    Conformal changes of scalar curvature, the Yamabe functional, Aubin's threshold and Schoen's solution, concentration compactness and bubbles, and why Perelman's log-Sobolev minimisers always exist.

  3. 9B.6
    Scalar Curvature and TopologyBook 9B · Comparison, Convergence and Heat on Manifolds

    Positive scalar curvature, its obstructions, and the positive mass theorem.