Higher Airy structures and topological recursion for singular spectral curves

We give elements towards the classification of quantum Airy structures based on the W.glr/-algebras at self-dual level based on twisted modules of the Heisenberg VOA of glr for twists by arbitrary elements of the Weyl group Sr. In particular, we construct a large class of such quantum Airy structures. We show that the system of linear ODEs forming the quantum Airy structure and determining uniquely its partition function is equivalent to a topological recursion à la Chekhov–Eynard–Orantin on singular spectral curves. In particular, our work extends the definition of the Bouchard–Eynard topological recursion (valid for smooth curves) to a large class of singular curves and indicates impossibilities to extend naively the definition to other types of singularities. We also discuss relations to intersection theory on moduli spaces of curves, giving a general ELSV-type representation for the topological recursion amplitudes on smooth curves, and formulate precise conjectures for application in open r-spin intersection theory.