AKT-09/HW2

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In Preparation

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

Solve the following problems and submit them in class by October 29, 2009:

Problem 1.

  1. Find a concise algorithm to compute the weight system [math]\displaystyle{ W_{so} }[/math] associated with the Lie algebra [math]\displaystyle{ so(N) }[/math] in its defining representation.
  2. Verify that your algorithm indeed satisfies the [math]\displaystyle{ 4T }[/math] relation.

Problem 2. The Kauffman polynomial [math]\displaystyle{ F(K)(a,z) }[/math] (see [Kauffman]) of a knot or link [math]\displaystyle{ K }[/math] is [math]\displaystyle{ a^{-w(K)}L(K) }[/math] where [math]\displaystyle{ w(L) }[/math] is the writhe of [math]\displaystyle{ K }[/math] and where [math]\displaystyle{ L(K) }[/math] is the regular isotopy invariant defined by the skein relations

[math]\displaystyle{ L(s_\pm)=a^{\pm 1}L(s)) }[/math]

(here [math]\displaystyle{ s }[/math] is a strand and [math]\displaystyle{ s_\pm }[/math] is the same strand with a [math]\displaystyle{ \pm }[/math] kink added) and

[math]\displaystyle{ L(\backoverslash)+L(\slashoverback) = z\left(L(\smoothing)+L(\hsmoothing)\right) }[/math]

and by the initial condition [math]\displaystyle{ L(\bigcirc)=1 }[/math]. State and prove the relationship between [math]\displaystyle{ F }[/math] and [math]\displaystyle{ W_{so} }[/math].

Problem 3.

Mandatory but unenforced. Find yourself in the class photo and identify yourself as explained in the photo page.

AKT-09-ClassPhoto.jpg

[Kauffman] ^  L. H. Kauffman, An invariant of regular isotopy, Trans. Amer. Math. Soc. 312 (1990) 417-471.