We prove that the GromovHausdorff compactification of the moduli space of KhlerEinstein Del Pezzo surfaces in each degree agrees with certain algebro-geometric compactification. In particular, this recovers Tians theorem on the existence of KhlerEinstein metrics on smooth Del Pezzo surfaces and classifies all the degenerations of such metrics. The proof is based on a combination of both algebraic and differential geometric techniques.

In this paper we introduce the interpolationdegeneration strategy to study KhlerEinstein metrics on a smooth Fano manifold with cone singularities along a smooth divisor that is proportional to the anti-canonical divisor. By interpolation we show the angles in (0, 2] that admit a conical KhlerEinstein metric form a connected interval, and by degeneration we determine the boundary of the interval in some important cases. As a first application, we show that there exists a KhlerEinstein metric on P 2 with cone singularity along a smooth conic (degree 2) curve if and only if the angle is in (/2, 2]. When the angle is 2/3 this proves the existence of a SasakiEinstein metric on the link of a three dimensional <i>A</i> ₂ singularity, and thus answers a question posed by GauntlettMartelliSparksYau. As a second application we prove a version of Donaldsons conjecture about conical Khler

We annnounce a proof of the fact that a K-stable Fano manifold admits a Kahler-Einstein metric and give a brief outline of the proof.

The main purpose of this paper is to prove a general result about the geometry of holomorphic line bundles over Khler manifolds. This result is essentially a partial verification of a conjecture of Tian [30] and Tian has, over many years, highlighted the importance of the question for the existence theory of KhlerEinstein metrics. We will begin by stating this main result.

This is the first of a series of three papers which prove the fact that a K-stable Fano manifold admits a Khler-Einstein metric. The main result of this paper is that a Khler-Einstein metric with cone singularities along a divisor can be approximated by a sequence of smooth Khler metrics with controlled geometry in the Gromov-Hausdorff sense.