引入了多重次调和函数的复奇性指数,并证明了其半连续性的一般结果。这个概念包含了几个类似的概念作为一个特例,这些概念已经被Arnold和Varchenko考虑过,主要用于研究超曲面奇点。多重次调和的版本在某种程度上是基于减少代数的情况下,但它也考虑到了更多的定量信息的极大兴趣,复分析和复杂的微分几何。作为一个应用程序,我们给出了一个新的推导准则的存在凯勒-爱因斯坦度量的某些法诺orbifolds,以下纳德尔的原始想法(但激烈的简化技术,一旦半连续性的结果是理所当然的)。这样,得到了3个新的具有商奇点的刚性Kähler-Einstein Del Pezzo曲面的例子.
英文摘要:
We introduce complex singularity exponents of plurisubharmonic functions and prove a general semi-continuity result for them. This concept contains as a special case several similar concepts which have been considered e.g. by Arnold and Varchenko, mostly for the study of hypersurface singularities. The plurisubharmonic version is somehow based on a reduction to the algebraic case, but it also takes into account more quantitative informations of great interest for complex analysis and complex differential geometry. We give as an application a new derivation of criteria for the existence of Kähler-Einstein metrics on certain Fano orbifolds, following Nadel's original ideas (but with a drastic simplication in the technique, once the semi-continuity result is taken for granted). In this way, 3 new examples of rigid Kähler-Einstein Del Pezzo surfaces with quotient singularities are obtained.
Restrictions on the Singularity Content of a Fano Polygon
我们确定限制的奇异性内容的法诺多边形,或相当于某些orbifold德尔佩佐表面。我们建立的1/R(1,1)奇异的最大数量的剩余奇异篮子的界限。特别地,不存在没有T-奇点且篮子由(i){k x 1/R(1,1)}给出的Fano多边形,其中k是正整数且R>4,或(ii){1/R1(1,1),1/R2(1,1),1/R3(1,1)}。
我们引入了Fano多边形极小性的概念。我们表明,到突变,只有100多个Fano多边形与给定的奇异性内容,并给出一个算法来确定这种多边形的突变等价类。这是使用镜像对称对orbifold del Pezzo曲面进行分类的程序中的关键步骤。作为一个应用程序,我们分类所有的Fano多边形,使相应的复曲面是qG-变形等价于(i)一个光滑的表面;或(ii)一个表面只有1/3(1,1)型奇点。