有理等单值形变系统的哈密顿结构
摘要
将等单值形变系统的哈密顿方法推广到包含黎曼球面上具有任意庞加莱秩非正则奇点的泛型有理协变导数算子。具有给定极点次数的有理联络的空间上承载一个自然泊松结构,对应于 loop algebra 的对偶空间 上的标准经典有理 R-矩阵结构。通过将形变参数识别为相空间上的 Casimir 函数,获得了由谱不变量生成的等谱系统的非自治等单值对应物。这些被证明与确定非正则奇点附近局部渐近行为的高阶 Birkhoff 不变量以及极点位置相一致。无穷小等单值形变被证明由哈密顿向量场与一个显式导数向量场之和生成,该导数向量场横截于辛叶层。Casimir 元作为补充辛叶上坐标的坐标,并由形式单值的指数扩充,定义了它们之间的局部辛同胚。显式导数向量场保持泊松结构并定义一个平坦横截联络,张成一个可积分布,其叶在局部可识别为自由阿贝尔群的轨道。在这些作用下的商流形上,无穷小等单值形变向量场的投影给出了对应于 Birkhoff 不变量和极点位置对偶的谱不变量的交换哈密顿向量场。
引用
@article{arxiv.2212.06880,
title = {Hamiltonian structure of rational isomonodromic deformation systems},
author = {M. Bertola and J. Harnad and J. Hurtubise},
journal= {arXiv preprint arXiv:2212.06880},
year = {2023}
}
备注
V6. 46 pages. To comply with J. Math. Phys. formatting requirements, the abstract was reduced to one paragraph and the table of contents and highlighting of theorems were removed. Comparison comments were added after Theorems 3.2 and 3.3. The summation limits were made more explicit in eqs. (3.15), (3.17). Ref. [19] was corrected