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arXiv math/0003220math.DGmath.AG
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特殊的拉格朗日子流形与代数复杂性一环面作用

Special Lagrangian submanifolds and Algebraic complexity one Torus Actions

Edward Goldstein

摘要:

在本文的第一部分中,我们考虑具有代数(n-1)-Torus作用的紧致代数流形M^2n。证明了M的典范丛存在T-不变亚纯截面$σ$。任何这样的$σ$定义除数D。在补M '= M-D上,我们有一个典范丛的平凡化和一个T作用。若M'的第一上同调为零,则文[2]的结果意味着M'上存在一个特殊拉格朗日纤维化。我们研究了M中纤维的紧化,并给出了M '上SLag纤维化的例子,包括M'的第一上同调不为零的情形。本文第二部分研究了M中的Calabi-Yau超曲面。我们假定$σ$是M的反典范丛的全纯截面$η$的逆。我们将看到,在某些假设下,可以在除数D s. t的光滑部分D'上选择一个全纯体积形式。T作用量的轨道给出D'上关于度规的SLag纤维化,由M导出。$η$附近的横截$η_j$定义了M中光滑的Calabi-Yau超曲面D_j。我们将证明,可以将D'上的SLag纤维化变形为D_j上的大部分SLag纤维化。这种构造适用于例如CP ^4中的五次D_j或格拉斯曼G(2,4)中的Calabi-Yau超曲面。

英文摘要:

In the first part of this paper we consider compact algebraic manifolds M^2n with an algebraic (n-1)-Torus action. We show that there is a T-invariant meromorphic section $σ$ of the canonical bundle of M. Any such $σ$ defines a divisor D. On the complement M'=M-D we have a trivialization of the canonical bundle and a T-action. If the first cohomology of M' vanishes, then results of [2] imply that there is a Special Lagrangian (SLag) fibration on M'. We study how the fibers compactify in M and give examples of SLag fibrations on M', including some cases there the first cohomology of M' doesn't vanish. In the second part of the paper we study Calabi-Yau hypersurfaces in M. We assume that $σ$ is an inverse of a holomorphic section $η$ of the anti-canonical bundle of M. We will see that under certain assumptions one can choose a holomorphic volume form on the smooth part D' of the divisor D s.t. orbits of the T-action give a SLag fibration on D' with respect to the metric, induced from M. Transversal sections $η_j$ near $η$ define smooth Calabi-Yau hypersurfaces D_j in M. We will show that one can deform the SLag fibration on D' to SLag fibrations on large parts of D_j. This construction applies for instance for D_j being quintics in CP^4 or Calabi-Yau hypersurfaces in the Grassmanian G(2,4).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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