Knot Invariants  

In General > s.a. energy; topological field theories.
* Idea: Can be generated as coefficients of polynomials using group theory; Braids can be used as a calculational tool.
* Alexander polynomial: Satisfies k+1(t) = k(t) 1(t).
  Examples: unknot(t) = 1; trefoil(t) = t 2t + 1; figure 8(t) = t 2 – 3t + 1.
* Conway polynomial: Defined by Cunknot(z) = 1 and the skein relations CL_+(z) – CL_–(z) = z CL_0(z), where the L's refer to the two possibilities for a crossing in a plane projection and to the crossing replaced by the lines reconnected in such a way that they do not cross; To extend it to double intersections, define CL_W = CL_0 and CL_I = (CL_+ + CL_–) for the two routings.
* Helicity: A second order integral in field amplitudes.
* Kauffman bracket polynomial:
* Unknotting number: The minimal number of self-crossings needed to obtain the unknot.
* And quantum groups: For every simple Lie algebra there is a Hopf algebra Uq(), and a polynomial link invariant; For example, Uq(sl2) corresponds to the Jones polynomial; HOMFLY.

References > s.a. knot theory [for generalized knots].
@ General: Buck & Flapan JPA(07) [topological characterization].
@ Polynomials: Akutsu & Wadati JPSJ(87), et al JPSJ(87), JPSJ(88); Jones AM(87); Lickorish & Millett Top(87); Deguchi et al JPSJ(88); Akutsu et al JPSJ(88); Kauffman IJMPA(90); Broda PLB(91), JMP(94); Suffczynski PLA(96) [rep]; Labastida & Mariño JKTR(02)m.QA/01.
@ Alexander-Conway polynomial: Kauffman Top(81); Friedman Top(04) [generalization]; Tsutsumi & Yamada Top(04) [and Dehn surgery]; Garoufalidis & Teichner JDG(04) [trivial polynomial].
@ Jones polynomial: Jones BAMS(85); Kauffman Top(87); Witten CMP(89) [and Chern-Simons theory]; Zulli Top(95), Chang & Shrock PhyA(01)mp/01 [computation]; Subramaniam & Ramadevi qp/02, Lomonaco & Kauffman qp/06, Garnerone et al LP(06)qp [quantum computation]; Loebl a0705 [from the permanent of a matrix]; Kauffman & Lomonaco a0706-in [algorithms]; > s.a. spin networks.
@ HOMFLY: Freyd et al BAMS(85); Labastida & Mariño IJMPA(95) [torus knots, from Chern-Simons]; Labastida & Pérez JMP(96)qa/95 [for torus knots, and Kauffman].
@ Third-order invariant: Berger JPA(90); Evans & Berger in(92).
@ Enumeration: Jacobsen & Zinn-Justin mp/01, mp/01 [transfer matrix approach].
@ Classification algorithms: Aneziris ht/94-in, qa/95, qa/95, qa/96, qa/96-in, qa/97-in; Flammini & Stasiak PRS(07).
@ And quantum groups: Turaev 94 [r Kuperberg BAMS(96)]; Sawin BAMS(96); Nikshych et al T&A(02).
@ And 3-manifolds: Blanchet et al Top(92) [Kauffman bracket and 3-manifold invariants]; Kauffman & Baadhio ed-93 [quantum field theory methods, quantum topology]; Eisermann Top(04).
@ And embedded graphs: Moffatt EJC(08) [Bollobás–Riordan polynomial].
@ Related topics: Adams PAMS(89) + refs [Gromov invariant]; O'Hara Top(91) [energy]; Akhmetiev & Ruzmaikin JGP(95) [Sato-Levine as 4th-order integral]; Álvarez & Labastida JKTR(96) [torus knots, Vassiliev]; Gukov a0706-in [homological, from topological gauge theories].


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