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arXiv 2104.12988math.DS
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多项式哈密顿微分系统等时中心的拓扑性质

Topological properties on isochronous centers of polynomial Hamiltonian differential systems

Guangfeng Dong

AI总结:

本文研究n次复多项式哈密顿微分系统等时中心的拓扑性质,证明消没圈平凡性的条件、给出等时性的简单必要条件,并建立Gavrilov问题与偶次实哈密顿系统非等时性猜想的关联。

摘要:

本文研究具有等时中心的n次复多项式哈密顿微分系统的拓扑性质。首先,我们证明:若包含等时中心的临界水平曲线仅含单个奇点,且周期1-形式在充分接近临界曲线的水平曲线上的无穷远点处不存在留数为零的极点,则与该中心相关的消没圈在一般水平曲线的射影闭包的一维同调群中是平凡的。该结果在相对简单的条件下对L. Gavrilov提出的一个问题给出了肯定回答,可用于实现对ℂ²上雅可比猜想的等价描述。其次,我们得到了一个十分简单但有用的哈密顿系统等时性必要条件:哈密顿函数的(n+1)次齐次部分必须含有一个重数不小于(n+1)/2的因子。第三,我们揭示了Gavrilov问题与X. Jarque和J. Villadelprat提出的关于偶次n次实哈密顿系统非等时性猜想之间的关联。

英文摘要:

In this paper, we study the topological properties of complex polynomial Hamiltonian differential systems of degree $n$ having an isochronous center. Firstly, we prove that if the critical level curve possessing an isochronous center contains only a single singular point, and the period $1$-form does not have poles with zero residue at infinity on level curves sufficiently close to the critical curve, then the vanishing cycle associated to this center is trivial in the 1-dimensional homology group of the projective closure of a generic level curve. Our result provides a positive answer to a question asked by L. Gavrilov under relatively simple conditions and can be applied to achieve an equivalent description of the Jacobian conjecture on $\mathbb{C}^2$. Secondly, we obtain a very simple but useful necessary condition for isochronicity of Hamiltonian systems, which is that the $(n+1)$-degree part of the Hamiltonian function must have a factor with multiplicity no less than $(n+1)/2$. Thirdly, we show a relation between Gavrilov's question and the conjecture proposed by X. Jarque and J. Villadelprat on the non-isochronicity of real Hamiltonian systems of even degree $n$.

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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