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In this paper we present several curvature estimates and convergence results for solutions of the Ricci flow. The curvature estimates depend on smallness of certain local space-time integrals of the norm of the Riemann curvature tensor,…

Differential Geometry · Mathematics 2007-07-17 Rugang Ye

In this paper we have studied the class of Finsler metrics, called C3-like metrics which satisfy the un-normal and normal Ricci flow equation and proved that such metrics are Einstein.

Differential Geometry · Mathematics 2021-07-13 Ranadip Gangopadhyay , Bankteshwar Tiwari

We consider the Ricci flow equation for invariant metrics on compact and connected homogeneous spaces whose isotropy representation decomposes into two irreducible inequivalent summands. By studying the corresponding dynamical system, we…

Differential Geometry · Mathematics 2012-09-17 Maria Buzano

If we want to deform a compact Riemannian manifold with boundary using Ricci flow, we first need to decide on appropriate boundary conditions. We would like these conditions to reflect the geometric nature of the flow and allow for a…

Differential Geometry · Mathematics 2024-03-15 Rasmus Jouttijärvi

We develop the theory of left-invariant generalized pseudo-Riemannian metrics on Lie groups. Such a metric accompanied by a choice of left-invariant divergence operator gives rise to a Ricci curvature tensor and we study the corresponding…

Differential Geometry · Mathematics 2023-02-22 Vicente Cortés , David Krusche

We study the Ricci flow for the Lorentzian Einstein-Hilbert action. We show that Einstein gravity emerges as a fixed point of the Einstein-Ricci flow equations and derive a renormalization group flow in Euclidean signature. By considering…

General Relativity and Quantum Cosmology · Physics 2021-10-05 Aditya Dhumuntarao

In this paper, we use a Killing form on a Riemannian manifold to construct a class of Finsler metrics. We find equations that characterize Einstein metrics among this class. In particular, we construct a family of Einstein metrics on $S^3$…

Differential Geometry · Mathematics 2017-03-08 Xinyue Cheng , Zhongmin Shen

We study the modified Ricci solitons as a new class of Einstein type metrics that contains both Ricci solitons and $n$-quasi-Einstein metrics. This class is closely related to the construction of the Ricci solitons that are realised as…

Differential Geometry · Mathematics 2025-10-16 Antonio Airton Freitas Filho

We establish variational formulas for Ricci upper and lower bounds, as well as a derivative formula for the Ricci curvature. As applications, constant curvature manifolds, Einstein manifolds and Ricci parallel manifolds are identified,…

Differential Geometry · Mathematics 2017-11-28 Feng-Yu Wang

In a number of physically important cases, the nonholonomically (nonintegrable) constrained Ricci flows can be modelled by exact solutions of Einstein equations with nonhomogeneous (anisotropic) cosmological constants. We develop two…

Mathematical Physics · Physics 2009-02-17 Sergiu I. Vacaru

We consider almost Einstein solitons $(V,\lambda)$ in a Riemannian manifold when $V$ is a gradient, a solenoidal or a concircular vector field. We explicitly express the function $\lambda$ by means of the gradient vector field $V$ and…

Differential Geometry · Mathematics 2025-08-04 Adara M. Blaga , Dan Radu Latcu

Until recently, Ricci flow was viewed almost exclusively as a way of deforming Riemannian metrics of bounded curvature. Unfortunately, the bounded curvature hypothesis is unnatural for many applications, but is hard to drop because so many…

Differential Geometry · Mathematics 2014-09-01 Peter M. Topping

In this paper we employ numerical methods to study the Einstein equation \[ Ric(g)=\lambda\, g, \] where $Ric$ is the Ricci tensor and $\lambda$ is the Einstein constant, restricted to a class of full flag manifolds. These metrics describe…

Differential Geometry · Mathematics 2016-03-17 Lino Grama , Ricardo Miranda Martins

We present a monotonic expression for the Ricci flow, valid in all dimensions and without curvature assumptions. It is interpreted as an entropy for a certain canonical ensemble. Several geometric applications are given. In particular, (1)…

Differential Geometry · Mathematics 2007-05-23 Grisha Perelman

We survey some recent work using Ricci flow to create a class of local definitions of weak lower scalar curvature bounds that is well defined for $C^0$ metrics. We discuss several properties of these definitions and explain some…

Differential Geometry · Mathematics 2020-12-18 Paula Burkhardt-Guim

In this paper, we study an important class of Finsler metrics--square metrics. We give two expressions of such metrics in terms of a Riemannian metric and a 1-form. We show that Einstein square metrics can be classified up to the…

Differential Geometry · Mathematics 2012-09-19 Zhongmin Shen , Changtao Yu

We prove dynamical stability and instability theorems for compact Einstein metrics under the Ricci flow. We give a nearly complete charactarization of dynamical stability and instability in terms of the conformal Yamabe invariant and the…

Differential Geometry · Mathematics 2020-07-20 Klaus Kroencke

We introduce a variation of the classical Ricci flow equation that modifies the unit volume constraint of that equation to a scalar curvature constraint. The resulting equations are named the Conformal Ricci Flow Equations because of the…

Differential Geometry · Mathematics 2009-11-10 Arthur E. Fischer

We derive one unified formula for Ricci curvature tensor on arbitrary warped product manifold by introducing a new notation for the lift vector and the Levi-Civita connection.This formula is helpful to further consider Ricci flow (RF) and…

Differential Geometry · Mathematics 2015-03-20 Wei-Jun Lu

All known examples of homogeneous Einstein metrics of negative Ricci curvature can be realized as left-invariant Riemannian metrics on solvable Lie groups. After defining a notion of maximal symmetry among left-invariant Riemannian metrics…

Differential Geometry · Mathematics 2015-07-31 Carolyn S. Gordon , Michael R. Jablonski