发表机构
State Key Laboratory of Mathematical Sciences, Academy of Mathematics and Systems Science, Chinese Academy of Sciences; School of Mathematical Sciences, University of Chinese Academy of Sciences(中国科学院数学与系统科学研究院数学科学重点实验室; 中国科学院大学数学科学学院)
机构由 AI 辅助整理,请以论文原文为准。AI 中文总结
该研究分类了复射影空间中维数≥2的三次超曲面补空间的Oka性质,通过覆盖、喷流构造、投影及相关定理完成分类,确定了例外非Oka补空间的构型。
AI 中文摘要
我们对复射影空间中维数至少为2的三次超曲面的补空间进行了分类,包含可约与非约化三次超曲面。该补空间为Oka空间,除非三次超曲面是三张不同超平面的并集且包含一个余维数为2的公共射影子空间;这种例外补空间不是Oka空间。对于光滑三次超曲面,我们过渡到补空间的非分歧循环三重覆盖,并沿剩余仿射二次曲线构造保补空间的喷流。在三次曲面上,27条直线构成有限支配族;在更高维空间中,我们对喷流进行重标度,使其从沿直线的爆破中下降,并利用Kaliman–Zaidenberg的切转移几何,使喷流的切方向在每一点张成空间。对于不可约奇异三次超曲面,从奇异点的投影、Kusakabe的局部化定理以及Hanysz关于亚纯图补空间的定理,可实现对维数的归纳;可约三次超曲面则归约为次数至多为2的多项式定义的仿射超曲面的补空间,显式完全向量场与初等标准型可分离出例外构型。
英文摘要
Let $D\subset\mathbb{P}^n$, $n\geqslant2$, be an arbitrary cubic hypersurface, and let $D_{\mathrm{red}}$ denote its reduced support. We prove that $\mathbb{P}^n\setminus D$ is holomorphically elliptic, and hence Oka, unless $D_{\mathrm{red}}$ is the union of three distinct hyperplanes containing a common codimension-two linear subspace. In the exceptional case, $\mathbb{P}^n\setminus D\cong(\mathbb{C}\setminus\{0,1\})\times\mathbb{C}^{n-1}$, so the complement is not Oka. As applications, we prove that, for every elliptic curve $E$, the space of degree-three holomorphic maps $E\to\mathbb{P}^1$, and the space of degree-three holomorphic self-maps of $\mathbb{P}^1$, are both holomorphically elliptic, and hence Oka. The second application is connected with the classification through an irreducible cubic hypersurface in $\mathbb{P}^4$.
Comments28 pages