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arXiv 1112.3263math.DG
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双环面上平坦仿射结构的形变

The deformations of flat affine structures on the two-torus

Oliver Baues

摘要:

定义双环面上平坦仿射结构的变形空间的模问题的群作用是仿射群$\Aff(2)$在$\bbR^2$上的作用。由于这个作用有非紧稳定子$\GL(2,\bbR)$,所以其基础的局部齐次几何是高度非黎曼的。本文描述了双环面上所有平坦仿射结构的形变空间。在这种情况下,有趣的现象出现在变形空间的拓扑中,例如,它是\emph{not}一个T2空间。这与常曲率度量或曲面上的共形结构的情况形成对比,这在经典的泰希米勒理论中遇到。作为我们关于环面上平坦仿射结构的变形空间的主要结果,我们证明了从变形空间到环面的基本群到仿射群的同态的共轭类簇的完整映射是局部同胚。

英文摘要:

The group action which defines the moduli problem for the deformation space of flat affine structures on the two-torus is the action of the affine group $\Aff(2)$ on $\bbR^2$. Since this action has non-compact stabiliser $\GL(2,\bbR)$, the underlying locally homogeneous geometry is highly non-Riemannian. In this article, we describe the deformation space of all flat affine structures on the two-torus. In this context interesting phenomena arise in the topology of the deformation space, which, for example, is \emph{not} a Hausdorff space. This contrasts with the case of constant curvature metrics, or conformal structures on surfaces, which are encountered in classical Teichmüller theory. As our main result on the space of deformations of flat affine structures on the two-torus we prove that the holonomy map from the deformation space to the variety of conjugacy classes of homomorphisms from the fundamental group of the two-torus to the affine group is a local homeomorphism.

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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