From quantum curves to topological string partition functions
Ioana Coman, Elli Pomoni, Jörg Teschner
TL;DR
This work presents a non-perturbative reconstruction of the topological string partition function $Z_{ m top}$ for certain local Calabi–Yau manifolds by quantising their defining curves into quantum curves and solving the accompanying Riemann–Hilbert problem. The central device is the isomonodromic tau-function, whose chamber-dependent normalisations encode different phases in the extended Kähler moduli space; these tau-functions admit generalised theta-series expansions that reproduce chamber-specific topological-string data. By relating quantum curves to ${ m D}$-modules, opers with apparent singularities, and isomonodromic deformations, the authors connect non-perturbative string data to free fermion partition functions and conformal blocks, with abelianisation providing a canonical coordinate framework. The results are checked against topological vertex calculations in the main example (the SU$(2)$, $N_f=4$ theory) and lead to a coherent picture in which integrable structures govern quantum corrections and chamber structure, offering a path to generalisations via spectral networks and beyond.
Abstract
This paper describes the reconstruction of the topological string partition function for certain local Calabi-Yau (CY) manifolds from the quantum curve, an ordinary differential equation obtained by quantising their defining equations. Quantum curves are characterised as solutions to a Riemann-Hilbert problem. The isomonodromic tau-functions associated to these Riemann-Hilbert problems admit a family of natural normalisations labelled by the chambers in the extended Kähler moduli space of the local CY under consideration. The corresponding isomonodromic tau-functions admit a series expansion of generalised theta series type from which one can extract the topological string partition functions for each chamber.
