K\"ahler Ricci flow with vanished Futaki invariant

We study the convergence of the K\"ahler-Ricci flow on a compact K\"ahler manifold $(M,J)$ with positive first Chern class $c_1(M;J)$ and vanished Futaki invariant on $\pi c_1(M;J)$. As the application we establish a criterion for the stability of the K\"ahler-Ricci flow (with perturbed complex structure) around a K\"ahler-Einstein metric with positive scalar curvature, under certain local stable condition on the dimension of holomorphic vector fields. In particular this gives a stability theorem for the existence of K\"ahler-Einstein metrics on a K\"ahler manifold with possibly nontrivial holomorphic vector fields.Comment: 23 pages; Remark 4.1 changed due to the comments of Valentino Tosatt

Degeneration of K\"ahler-Ricci solitons

Let $(Y, d)$ be a Gromov-Hausdorff limit of $n$-dimensional closed shrinking K\"ahler-Ricci solitons with uniformly bounded volumes and Futaki invariants. We prove that off a closed subset of codimension at least 4, Y is a smooth manifold satisfying a shrinking K\"ahler-Ricci soliton equation. A similar convergence result for K\"ahler-Ricci flow of positive first Chern class is also obtained.Comment: 24 page

Convergence of K\"ahler-Ricci flow on lower dimensional algebraic manifolds of general type

In this paper, we prove that the $L^4$-norm of Ricci curvature is uniformly bounded along a K\"ahler-Ricci flow on any minimal algebraic manifold. As an application, we show that on any minimal algebraic manifold $M$ of general type and with dimension $n\le 3$, any solution of the normalized K\"ahler-Ricci flow converges to the unique singular K\"ahler-Einstein metric on the canonical model of $M$ in the Cheeger-Gromov topology

Relative volume comparison of Ricci Flow and its applications

In this paper, we derive a relative volume comparison estimate along Ricci flow and apply it to studying the Gromov-Hausdorff convergence of K\"ahler-Ricci flow on a minimal manifold. This new estimate generalizes Perelman's no local collapsing estimate and can be regarded as an analogue of the Bishop-Gromov volume comparison for Ricci flow.Comment: 28 pages; minor change in the proof of Lemma 3.

Regularity of K\"ahler-Ricci flow

In this short note we announce a regularity theorem for K\"ahler-Ricci flow on a compact Fano manifold (K\"ahler manifold with positive first Chern class) and its application to the limiting behavior of K\"ahler-Ricci flow on Fano 3-manifolds. Moreover, we also present a partial $C^0$ estimate to the K\"ahler-Ricci flow under the regularity assumption, which extends previous works on K\"ahler-Einstein metrics and shrinking K\"ahler-Ricci solitons (cf. \cite{Ti90}, \cite{DoSu12}, \cite{Ti12}, \cite{PSS12}). The detailed proof will appear in \cite{TiZh13}

Regularity of K\"ahler-Ricci flows on Fano manifolds

In this paper, we will establish a regularity theory for the K\"ahler-Ricci flow on Fano $n$-manifolds with Ricci curvature bounded in $L^p$-norm for some $p > n$. Using this regularity theory, we will also solve a long-standing conjecture for dimension 3. As an application, we give a new proof of the Yau-Tian-Donaldson conjecture for Fano 3-manifolds. The results have been announced in \cite{TiZh12b}.Comment: Proof of results announced in arXiv:1304.2651v

Non-singular solutions to the normalized Ricci flow equation

In this paper we study non-singular solutions of Ricci flow on a closed manifold of dimension at least 4. Amongst others we prove that, if M is a closed 4-manifold on which the normalized Ricci flow exists for all time t>0 with uniformly bounded sectional curvature, then the Euler characteristic $\chi (M)\ge 0$. Moreover, the 4-manifold satisfies one of the following \noindent (i) M is a shrinking Ricci solition; \noindent (ii) M admits a positive rank F-structure; \noindent (iii) the Hitchin-Thorpe type inequality holds 2\chi (M)\ge 3|\tau(M)| where $\chi (M)$ (resp. $\tau(M)$) is the Euler characteristic (resp. signature) of M.Comment: 23 page

Non-singular solutions of normalized Ricci flow on noncompact manifolds of finite volume

The main result of this paper shows that, if $g(t)$ is a complete non-singular solution of the normalized Ricci flow on a noncompact 4-manifold $M$ of finite volume, then the Euler characteristic number $\chi(M)\geq0$. Moreover, $\chi(M)\neq 0$, there exist a sequence times $t_k\to\infty$, a double sequence of points $\{p_{k,l}\}_{l=1}^{N}$ and domains $\{U_{k,l}\}_{l=1}^{N}$ with $p_{k,l}\in U_{k,l}$ satisfying the followings: [(i)] \dist_{g(t_k)}(p_{k,l_1},p_{k,l_2})\to\infty as $k\to\infty$, for any fixed $l_1\neq l_2$; [(ii)] for each $l$, $(U_{k,l},g(t_k),p_{k,l})$ converges in the $C_{loc}^\infty$ sense to a complete negative Einstein manifold $(M_{\infty,l},g_{\infty,l},p_{\infty,l})$ when $k\to\infty$; [(iii)] \Vol_{g(t_{k})}(M\backslash\bigcup_{l=1}^{N}U_{k,l})\to0 as $k\to\infty$

Two generalizations of Cheeger-Gromoll splitting theorem via Bakry-\'{E}mery Ricci curvature

In this paper, we prove two generalized versions of the Cheeger-Gromoll splitting theorem via the non-negativity of the Bakry-\'Emery Ricci curavture on complete Riemannian manifolds.Comment: 14 page

Supremum of Perelman's entropy and K\"ahler-Ricci flow on a Fano manifold

In this paper, we extend the method in [TZhu5] to study the energy level $L(\cdot)$ of Perelman's entropy $\lambda(\cdot)$ for K\"ahler-Ricci flow on a Fano manifold. Consequently, we first compute the supremum of $\lambda(\cdot)$ in K\"ahler class $2\pi c_1(M)$ under an assumption that the modified Mabuchi's K-energy $\mu(\cdot)$ defined in [TZhu2] is bounded from below. Secondly, we give an alternative proof to the main theorem about the convergence of K\"ahler-Ricci flow in [TZhu3].Comment: 28 page