Highest weight vectors, shifted topological recursion and quantum curves
Raphaël Belliard, Vincent Bouchard, Reinier Kramer, Tanner Nelson
TL;DR
The paper develops a shifted extension of topological recursion by constructing shifted rs-Airy structures whose partition functions are highest weight vectors for $\mathcal{W}(\mathfrak{gl}_r)$ at self-dual or deformed levels. This framework yields shifted loop equations and a corresponding shifted topological recursion that produces symmetric correlators and a WKB-type quantum curve with $\hbar$-dependent terms; it also establishes a converse direction: an $\hbar$-connection of topological type must satisfy the same shift conditions. The results demonstrate that under the modular constraint $r=\pm1\pmod{s}$, the shifted construction recovers the full quantization spectrum of the $(r,s)$-spectral curve, including all operator orderings in special cases $s=1$ and $s=r-1$, and connect the algebraic, geometric, and analytic viewpoints via loop equations, wave-functions, and determinantal formulations. Overall, the work broadens the scope of topological recursion to access a wider class of quantum curves and clarifies the role of highest-weight shifts in the correspondence between Airy structures, WKB analysis, and quantum curves.
Abstract
We extend the theory of topological recursion by considering Airy structures whose partition functions are highest weight vectors of particular $\mathcal{W}$-algebra representations. Such highest weight vectors arise as partition functions of Airy structures only under certain conditions on the representations. In the spectral curve formulation of topological recursion, we show that this generalization amounts to adding specific terms to the correlators $ ω_{g,1}$, which leads to a ``shifted topological recursion'' formula. We then prove that the wave-functions constructed from this shifted version of topological recursion are WKB solutions of families of quantizations of the spectral curve with $ \hbar$-dependent terms. In the reverse direction, starting from an $\hbar$-connection, we find that it is of topological type if the exact same conditions that we found for the Airy structures are satisfied. When this happens, the resulting shifted loop equations can be solved by the shifted topological recursion obtained earlier.
