Polynomial recursion formula for linear Hodge integrals

Understand

We establish a polynomial recursion formula for linear Hodge integrals.

• It is obtained as the Laplace transform of the cut-and-join equation for the simple Hurwitz numbers.
• We show that the recursion recovers the Witten-Kontsevich theorem when restricted to the top degree terms, and also the combinatorial factor of the lambda_g formula as the lowest degree terms.