Paper · Aug 20, 2026

Ricci Soliton Classification on

Anton Khaliapin

As on arXiv

Abstract

We study Ricci solitons on the Riemannian manifold equipped with the standard metric. A complete classification of soliton vector fields is obtained: they form a four-dimensional affine space, namely a translate of the Killing algebra . All corresponding solitons are expanding. In addition, gradient solitons are fully characterized and shown to form a one-parameter subfamily of the complete family of soliton fields. As a byproduct, every soliton vector field turns out to be affine, preserving the Levi-Civita connection, the curvature tensor, and the Ricci tensor.

Submitted
Aug 20, 2026
Subjects
math.DG

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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.

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  1. Ricci solitons with an orthogonally intransitive 2-dimensional Abelian Killing algebra

    Diego Catalano Ferraioli

    Topics 4-manifolds, Ricci solitons · Shared terms “Killing algebra”, “vector field”, “four dimensional”

  2. A note on the classification of four-dimensional gradient steady and expanding Ricci solitons

    Huai-Dong Cao and Junming Xie

    Topics 4-manifolds, Ricci solitons · Shared terms “four dimensional”, “addition”

  3. On curvature estimates for four-dimensional gradient Ricci solitons

    Huai-Dong Cao

    Topics 4-manifolds, Ricci solitons · Shared terms “four dimensional”, “addition”

  4. Rigidity of Gradient Shrinking Ricci Solitons with a Vanishing Bach-like Tensor and Related Variational Formulas

    James Siene

    Topics 4-manifolds, Ricci solitons · Shared terms “curvature tensor”, “four dimensional”

  5. Curvature estimates for four-dimensional complete gradient expanding Ricci solitons

    Huai-Dong Cao and Tianbo Liu

    Topics 4-manifolds, Ricci solitons · Shared terms “four dimensional”, “curvature tensor”

  6. On Euler characteristic and Hitchin-Thorpe inequality for four-dimensional compact Ricci solitons

    Xu Cheng, Ernani Ribeiro and Detang Zhou

    Topics 4-manifolds, Ricci solitons · Shared terms “four dimensional”, “addition”

  7. Pseudo-Riemannian Algebraic Ricci Solitons on Four-Dimensional Lie Groups

    Youssef Ayad

    Topics 4-manifolds, Ricci solitons · Shared terms “four dimensional”

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. 11B.1
    Ricci SolitonsBook 11B · Solitons, Compactness and Singularities

    Self-similar solutions: the Gaussian, cylinders, the cigar and the Bryant soliton.

  2. 12B.2
    The Asymptotic Soliton and Three-Dimensional ShrinkersBook 12B · κ-Solutions and Surgery

    Perelman's Proposition 11.2 proved with Morgan and Tian: the reduced-length bounds on κ-solutions, the limit of rescalings, the equality case, and the classification of shrinking solitons in dimensions two and three.