Geometric Perspective on Piecewise Polynomiality of Double Hurwitz Numbers

Cavalieri, Renzo ; Marcus, Steffen

Canadian mathematical bulletin, Tome 57 (2014) no. 4, pp. 749-764

Résumé

We describe double Hurwitz numbers as intersection numbers on the moduli space of curves ${{\overline{M}}_{g,n}}$ Using a result on the polynomiality of intersection numbers of psi classes with the Double Ramification Cycle, our formula explains the polynomiality in chambers of double Hurwitz numbers and the wall-crossing phenomenon in terms of a variation of correction terms to the $\varphi$ classes. We interpret this as suggestive evidence for polynomiality of the Double Ramification Cycle (which is only known in genera 0 and 1).

Détail

DOI : 10.4153/CMB-2014-031-6

Mots-clés : 14N35, double Hurwitz numbers, wall crossings, moduli spaces, ELSV formula

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