The Envelope of The Alexander Polynomial: Difference between revisions

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==The VS-Algebra Envelope of the Alexander Polynomial==
==The VS-Algebra Envelope of the Alexander Polynomial==

==Alexander-Conway, Precisely==

Let <math>C(z)</math> denote the Conway polynomial and <math>A(t)</math> denote the Alexander polynomial. By {{ref|Bar-Natan_Garoufalidis_96}} we know that

{{Equation*|<math>\frac{\hbar}{e^{\hbar/2}-e^{-\hbar/2}}C(e^{\hbar/2}-e^{-\hbar/2}) = \frac{\hbar}{e^{\hbar/2}-e^{-\hbar/2}}A(e^\hbar)</math>}}

is a canonical Vassiliev power series. Let d denote "half a bubble". The following theorem follows easily from the above canonicity statement and the fact that <math>W_C(d^{2n})=(-2\hbar^2)^n</math> (in shorter and less precise form, <math>\hbar=W_C(id/\sqrt2)</math>), where <math>W_C</math> is the weight system of the Alexander-Conway polynomial:

'''Theorem.''' Let <math>K</math> be a knot and let <math>Z(K)</math> be the Kontsevich integral of <math>K</math>. Then within the envelope of the Alexander-Conway polynomial,
{{Equation*|<math>Z(K) = \frac{id/\sqrt2}{e^{id/2\sqrt2}-e^{-id/2\sqrt2}} C(e^{id/2\sqrt2}-e^{-id/2\sqrt2}) = \frac{id/\sqrt2}{e^{id/2\sqrt2}-e^{-id/2\sqrt2}} A(e^{id/\sqrt2})</math>.}}

==References==

{{note|Bar-Natan_Garoufalidis_96}} Dror Bar-Natan and Stavros Garoufalidis, ''[http://www.math.toronto.edu/~drorbn/LOP.html#MMR On the Melvin-Morton-Rozansky Conjecture],'' Inventiones Mathematicae '''125''' (1996) 103-133.

Revision as of 20:20, 30 April 2007

In Preparation

The information below is preliminary and cannot be trusted! (v)

The Internal Kernel of the Alexander Polynomial

All that there is here comes from 06-1350/Class Notes for Tuesday October 24. Many further relevant facts are in arXiv:q-alg/9602014 by José M. Figueroa-O'Farrill, Takashi Kimura, Arkady Vaintrob and in arXiv:math.QA/0204346 by Jens Lieberum.

At the moment I know of just three relations in the internal kernel of the Alexander polynomial: the bubble relation, the H relation and the 4Y relation:

The Bubble Relation
The H Relation
The 4Y Relation

I have good reasons to suspect that there are further relations. But at the moment I don't know what they are, so below we will make do with what we have.

The VS-Algebra Envelope of the Alexander Polynomial

Alexander-Conway, Precisely

Let denote the Conway polynomial and denote the Alexander polynomial. By [Bar-Natan_Garoufalidis_96] we know that

is a canonical Vassiliev power series. Let d denote "half a bubble". The following theorem follows easily from the above canonicity statement and the fact that (in shorter and less precise form, ), where is the weight system of the Alexander-Conway polynomial:

Theorem. Let be a knot and let be the Kontsevich integral of . Then within the envelope of the Alexander-Conway polynomial,

.

References

[Bar-Natan_Garoufalidis_96] ^  Dror Bar-Natan and Stavros Garoufalidis, On the Melvin-Morton-Rozansky Conjecture, Inventiones Mathematicae 125 (1996) 103-133.