Jones polynomials

  1. We can focus on the computations of knots invariants in S3, because other three-manifold can be reduced to S3 by surgery: cut out a 2d thicken circle MR, make a diffeomorphism (glue to create genus?) to its boundary and then stick back (eg. stick a sphere with a handle). This can be seen by considering vice versa: S3 can be constructed to any three-manifold by surgery (compare their time slices).

    This operation results in a transformation on the states on MR. By applying surgery to the knots (MR), we can make knots move in S3 and do computations.

  2. For S3, we have expectation values uniquely decided by the skein relation (isotopic transformation). This can be proved by cutting out a ket with 4 marked points, replacing by other two proper kets (different knots in the same submanifold~different kets in the same Hilbert space), and noticing that the Hilbert space is 2d (4-pt, 2 conformal blocks) so these three kets are linear dependent.

  3. Similarly, we can prove the multiplicativity for the connected sum of manifolds with the unknotted and unlinked knots (marked points less than 3): cut into |a and b|, Z(M)=b|a, Z(M)Z(S3)=b|vv|a=Z(M1)Z(M2) (Hilbert space is 1d; this S3 doesn't have knots).