We recall a definition of an asymptotic invariant of classical link, which is called M-invariant. M-invariant is a special Massey integral, this integral has an ergodic form and is generalized for magnetic fields with open magnetic lines in a bounded 3D-domain. We present a proof that this integral is well defined. A combinatorial formula for M-invariant using the Conway polynomial is presented. The M-invariant is a higher invariant, it is not a function of pairwise linking numbers of closed magnetic lines. We discuss applications of M-invariant for MHD.

中文翻译：

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关于闭合磁力线的更高积分不变量，重新审视

我们回忆一下经典链接的渐近不变量的定义，称为M 不变量。M 不变量是一种特殊的梅西积分，该积分具有遍历形式，并被推广到有界 3 D域中具有开放磁力线的磁场。我们证明了这个积分是明确定义的。给出了使用康威多项式的M 不变量的组合公式。的中号-invariant是较高的不变的，它不是成对连接的闭合磁力线数的功能。我们讨论M- invariant 在 MHD 中的应用。