Prompted by the duality between open string theory on noncompact Calabi–Yau
threefolds and Chern–Simons theory on three-manifolds, M Mariño and C Vafa
conjectured a formula of one-partition Hodge integrals in term of invariants of the
unknot. Many Hodge integral identities, including the λg conjecture and
the ELSV formula, can be obtained by taking limits of the Mariño–Vafa
formula.
Motivated by the Mariño–Vafa formula and formula of Gromov–Witten
invariants of local toric Calabi–Yau threefolds predicted by physicists, J Zhou
conjectured a formula of two-partition Hodge integrals in terms of invariants of the
Hopf link and used it to justify the physicists’ predictions.
In this expository article, we describe proofs and applications of these two
formulae of Hodge integrals based on joint works of K Liu, J Zhou and the author.
This is an expansion of the author’s talk of the same title at the BIRS workshop TheInteraction of Finite Type and Gromov–Witten Invariants, November 15th–20th
2003.