bracket#
The bracket polynomial <.> (aka the Kauffman bracket) is a polynomial invariant of unoriented framed links. It is characterized by the following three rules: 1. <U> = 1, where U is the unknot. 2. <L_X> = A <L_0> + 1/A <L_inf> 3. <L ⊔ U> = (-A^2 - A^-2) <L> See Louis H. Kauffman, State models and the Jones polynomial. Topology 26 (1987), no. 3, 395–407.
Functions
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Return the (Kauffman) Bracket polynomial defined via the skein relations <L_X> = A <L_0> + 1/A <L_inf>, <L ⊔ U> = (-A^2 - A^-2) <L> and <unknot> = 1. :param k: Planar diagram :param normalize: should we normalize it by multiplying by the factor (-A^3)^wr(k), where wr is the writhe of the diagram d :return: (Laurent) polynomial in variable. |
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