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.]
An explicit formula for the $A$-polynomial of the knot having Conway's notation $C(2n,4)$ is computed up to repeated factors. Our polynomial contains exactly the same irreducible factors as the $A$-polynomial defined in~\cite{CCGLS1}.
We present an accurate detailed exposition of the proof of existence of the Alexander-Conway polynomial (of links in 3-dimensional space). Other proofs were given by J. Alexander, J. Conway, V. Mantourov and L. Kauffman.
A factorization of the Conway polynomial and covering linkage invariants
J. P. Levine证明了链环的Conway多项式是两个因子的乘积:一个是通过将链环的组成部分捆绑在一起而得到的纽结的Conway多项式;另一个是由以链环作为其闭包的弦链环的$\barμ$ -不变量确定的。我们给出了后者的另一种描述:行列式的矩阵,其条目是连接配对的无限循环覆盖空间的结补,其值在商领域的${\Bbb Z}[t,t^{-1}]$。此外,我们还给出了在$t=1$周围的连接对的Taylor展开式与T. D.科克伦事实上,$t-1$的幂的系数将是$S^3$中某些导出链路的环绕数。因此,Conway多项式的第一非零系数由$S^3$中的环绕数确定。这推广了J. Hoste的一个结果。
The Links--Gould invariant $\mathrm{LG}(L ; t_0, t_1)$ of a link $L$ is a two-variable quantum generalization of the Alexander--Conway polynomial $Δ_L(t)$ and has been shown to share some of its most geometric features in several recent works. Here we suggest that $\mathrm{LG}$ likely shares another of the Alexander polynomial's most distinctive - and mysterious - properties: for alternating links, the coefficients of the Links-Gould polynomial alternate and appear to form a log-concave two-indexed sequence with no internal zeros. The former was observed by Ishii for knots with up to 10 crossi…
Let $X$ be a $(2+1)$-dimensional globally hyperbolic spacetime with a Cauchy surface $Σ$ whose universal cover is homeomorphic to $\mathbb{R}^2$. We provide empirical evidence suggesting that the Jones polynomial detects causality in $X$. We introduce a new invariant of certain tangles related to the Conway polynomial, and prove that the Conway polynomial does not detect the connected sum of two Hopf links among relevant 3-component links, which suggests that the Conway polynomial does not detect causality in the scenario described.
In a recent paper, Allen and Swenberg investigated which link polynomials are capable of detecting causality in (2+1)-dimensional globally hyperbolic spacetimes. They ultimately suggested it is likely that the Jones Polynomial accomplishes this, while the Alexander-Conway polynomial, independently, is insufficient. As the Alexander-Conway polynomial on its own is not likely to detect causality an additional piece of information must be supplemented to the link polynomial. This paper aims to examine the ability of Alexander quandles, to distinguish the connected sum of two Hopf links and Allen-…