Chern-Simons Theory & Knot Invariants

Chern-Simons theory is a 3D topological QFT: Z=∫DA exp(ik/4π ∫Tr(A∧dA+⅔A∧A∧A)). Wilson loops W_R(K)=Tr P exp(∮_K A) are the observables — their expectation values give knot invariants including the Jones polynomial at q=e^(2πi/(k+2)).

Knot Selector

Linking # = —
Wilson loop:
W_R(K)=Tr P exp(∮A)

Jones polynomial:
⟨W⟩_CS = V_K(q)
q=e^(2πi/(k+2))

Framing anomaly:
Writhe shift by n
multiplies by q^(nθ)

Linking number:
lk(K,L)=½∮∮(r-r')/|r-r'|³