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手征性和Conway多项式

Chirality and the Conway polynomial

James Conant

摘要:

在最近与J. Mostovich和T.Stanford的工作中,作者发现,对于每个自然数n,康威多项式系数中的某个多项式是原始整数值n次瓦西里耶夫不变量,但模2,它变成n-1次。猜想然后自然地表明,这些原始不变量是全等整数值的程度n-1不变量。在本说明中,这个猜想的后果进行了探讨。在一个附加的假设下,证明了这个猜想蕴含着双头纽结的Conway多项式具有这样的性质:C(z)C(iz)C(z^2)是整系数幂级数环内的完满平方,或等价地,C(z)C(iz)C(z^2)的象是Z_4系数多项式环内的完满平方.事实上,对于某些整数系数的多项式f(z),可能是这样的情况,即双曲线纽结的Conway多项式总是可以写成f(z)f(-z),这实际上隐含了上述“完满平方“条件。事实上,通过川内和哈特利的工作,这是已知的所有负的双头螺旋结和所有强正的双头螺旋结。总的来说,它仍然没有解决,这篇论文可以被看作是一些证据,证明它确实是正确的。[添加2/22/12:值得注意的是最近的论文arXiv:1106.5634v1 [math.GT]由Ermotti,Hongler和Weber,它发现了一个反例的猜想,所有的康威多项式的双头结的形式f(z)f(-z)。有趣的是,对于幂级数f(z),他们的主要例子仍然满足C(z)C(iz)C(z^2)=f(z)^2,在作者看来,这使得本文的主要猜想更加引人注目。

英文摘要:

In recent work with J.Mostovoy and T.Stanford,the author found that for every natural number n, a certain polynomial in the coefficients of the Conway polynomial is a primitive integer-valued degree n Vassiliev invariant, but that modulo 2, it becomes degree n-1. The conjecture then naturally suggests itself that these primitive invariants are congruent to integer-valued degree n-1 invariants. In this note, the consequences of this conjecture are explored. Under an additional assumption, it is shown that this conjecture implies that the Conway polynomial of an amphicheiral knot has the property that C(z)C(iz)C(z^2) is a perfect square inside the ring of power series with integer coefficients, or, equivalently, the image of C(z)C(iz)C(z^2) is a perfect square inside the ring of polynomials with Z_4 coefficients. In fact, it is probably the case that the Conway polynomial of an amphicheiral knot always can be written as f(z)f(-z) for some polynomial f(z) with integer coefficients, and this actually implies the above "perfect squares" conditions. Indeed, by work of Kawauchi and Hartley, this is known for all negative amphicheiral knots and for all strongly positive amphicheiral knots. In general it remains unsolved, and this paper can be seen as some evidence that it is indeed true in general. [Added 2/22/12: Of note is the recent paper arXiv:1106.5634v1 [math.GT] by Ermotti, Hongler and Weber, which finds a counterexample to the conjecture that all Conway polynomials of amphicheiral knots are of the form f(z)f(-z). Intriguingly, their main example still satisfies C(z)C(iz)C(z^2)=f(z)^2 for a power series f(z), making the main conjecture of the present paper that much more compelling, in the author's opinion.]

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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