English

The Ricci tensor of a gradient Ricci soliton with harmonic Weyl tensor

Differential Geometry 2025-10-15 v1

Abstract

In this article, we give a new proof of a result due to J. Kim, which states that the Ricci tensor of a gradient Ricci soliton with dimension n4n \geq 4 and harmonic Weyl tensor has at most three distinct eigenvalues. This result constitutes an essential step in the classification of such manifolds, originally established by J. Kim in dimension 44 and subsequently extended to dimensions n5n\geq5. Our proof offers two notable advantages: it is shorter and does not require the use of any specialized moving frame.

Keywords

Cite

@article{arxiv.2510.11939,
  title  = {The Ricci tensor of a gradient Ricci soliton with harmonic Weyl tensor},
  author = {Valter Borges and Matheus Andrade Ribeiro de Moura Horácio and João Paulo dos Santos},
  journal= {arXiv preprint arXiv:2510.11939},
  year   = {2025}
}