The Laplace transform of the cut-and-join equation and the Bouchard-Marino conjecture on Hurwitz numbers

Understand

We calculate the Laplace transform of the cut-and-join equation of Goulden, Jackson and Vakil.

• The result is a polynomial equation that has the topological structure identical to the Mirzakhani recursion formula for the Weil-Petersson volume of the moduli space of bordered hyperbolic surfaces.
• We find that the direct image of this Laplace transformed equation via the inverse of the Lambert W-function is the topological recursion formula for Hurwitz numbers conjectured by Bouchard and Marino using topological string theory.