“…The coefficients of certain series expansions of correlation differentials are often solutions to problems in enumerative geometry and mathematical physics. In this way, topological recursion governs intersection theory on moduli spaces of curves [16], Weil-Petersson volumes of moduli spaces of hyperbolic surfaces [17], enumeration of ribbon graphs [29,10], stationary Gromov-Witten theory of P 1 [30,12], simple Hurwitz numbers and their generalisations [6,15,8,4], and Gromov-Witten theory of toric Calabi-Yau threefolds [5,18,19]. There are also conjectural relations to spin Hurwitz numbers [27] and quantum invariants of knots [7,1].…”