In this paper, we study the Ricci flow on higher dimensional compact manifolds. We prove that nonnegative isotropic curvature is preserved by the Ricci flow in dimensions greater than or equal to four. In order to do so, we introduce a new technique to prove that curvature functions defined on the orthonormal frame bundle are preserved by the Ricci flow. At a minimum of such a function, we comp...

Given a completely arbitrary surface, whether or not it has bounded curvature, or even whether or not it is complete, there exists an instantaneously complete Ricci flow evolution of that surface that exists for a specific amount of time [GT11]. In the case that the underlying Riemann surface supports a hyperbolic metric, this Ricci flow always exists for all time and converges (after scaling b...

In this paper we prove a conjecture by Feldman–Ilmanen–Knopf (2003) that the gradient shrinking soliton metric they constructed on the tautological line bundle over CP is the uniform limit of blow-ups of a type I Ricci flow singularity on a closed manifold. We use this result to show that limits of blow-ups of Ricci flow singularities on closed four-dimensional manifolds do not necessarily have...

Geometric monotone properties of the first nonzero eigenvalue of Laplacian form operator under the action of the Ricci flow in a compact nmanifold ( ) 2 ≥ n are studied. We introduce certain energy functional which proves to be monotonically non-decreasing, as an application, we show that all steady breathers are gradient steady solitons, which are Ricci flat metric. The results are also extend...

In this paper, we prove that the first eigenvalues of −∆+ cR (c ≥ 1 4 ) are nondecreasing under the Ricci flow. We also prove the monotonicity under the normalized Ricci flow for the cases c = 1/4 and r ≤ 0. 1. First eigenvalue of −∆+ cR Let M be a closed Riemannian manifold, and (M,g(t)) be a smooth solution to the Ricci flow equation ∂ ∂t gij = −2Rij on 0 ≤ t < T . In [Cao07], we prove that a...

The short time existence of Ricci flow on complete noncompact Riemannian manifolds with bounded curvature is proven by Shi [Sh1]. The uniqueness of such solutions is a difficult problem. Hsu studies this problem in dimension two [Hs], otherwise there is not any result about this problem. In the fundamental paper [Pe2] Perelman discussed a special family of solutions of Ricci flow on R, the so-c...

If a normalized Kähler-Ricci flow g(t), t ∈ [0,∞), on a compact Kähler manifold M , dimC M = n ≥ 3, with positive first Chern class satisfies g(t) ∈ 2πc1(M) and has curvature operator uniformly bounded in Ln-norm, the curvature operator will also be uniformly bounded along the flow. Consequently the flow will converge along a subsequence to a Kähler-Ricci soliton.

In this paper, we prove that Kähler-Ricci flow converges to a Kähler-Einstein metric (or a Kähler-Ricci soliton) in the sense of Cheeger-Gromov as long as an initial Kähler metric is very closed to gKE (or gKS) if a compact Kähler manifold with c1(M) > 0 admits a Kähler Einstein metric gKE (or a Kähler-Ricci soliton gKS). The result improves Main Theorem in [TZ3] in the sense of stability of Kä...

We give a simple proof for the ε-closeness of any region of large curvature of solution of three dimensional Ricci flow to a subset of an ancient κ-solution which was originally obtained by G. Perelman in his famous paper [14] on Ricci flow. We also give a detail proof of a result of [14] on the backward curvature estimates for the solutions of Ricci flow on closed three dimensional manifold wh...

These are notes on Perelman’s papers “The Entropy Formula for the Ricci Flow and its Geometric Applications” [40] and “Ricci Flow with Surgery on Three-Manifolds’ [41]. In these two remarkable preprints, which were posted on the ArXiv in 2002 and 2003, Grisha Perelman announced a proof of the Poincaré Conjecture, and more generally Thurston’s Geometrization Conjecture, using the Ricci flow appr...