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arXiv 0711.4086math.SG
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Hamilton群中的环:综述

Loops in the Hamiltonian group: a survey

Dusa McDuff

摘要:

本文介绍了关于各种流形(包括复曲面流形和一点爆破流形)中哈密顿回路同伦性质的一些最新结果。我们描述了一个圆作用在Hamilton群中不收缩的条件,并构造了一个辛流形M的环$\ga$的例子,该环具有这样的性质:与$\ga$光滑同位的环都不保持M上的任何辛形式.我们还讨论了Hamilton群具有无穷Hynomial直径的一些新的条件。其中一些方法是经典的(温斯坦的作用量同态和体积计算),而另一些则使用量子方法(赛德尔表示和谱不变量)。

英文摘要:

This note describes some recent results about the homotopy properties of Hamiltonian loops in various manifolds, including toric manifolds and one point blow ups. We describe conditions under which a circle action does not contract in the Hamiltonian group, and construct an example of a loop $\ga$ of diffeomorphisms of a symplectic manifold M with the property that none of the loops smoothly isotopic to $\ga$ preserve any symplectic form on M. We also discuss some new conditions under which the Hamiltonian group has infinite Hofer diameter. Some of the methods used are classical (Weinstein's action homomorphism and volume calculations), while others use quantum methods (the Seidel representation and spectral invariants).

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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