Topological gravity for arbitrary Dyson index

TL;DR

This paper introduces a generalized form of topological gravity parameterized by Dyson index eta, interpolating between different manifold types and universality classes, and investigates its structural properties and quantum chaotic behavior.

Contribution

It defines eta topological gravity via matrix model duality, explores its structural properties, geometric interpretation, and quantum chaos implications, extending previous models to arbitrary Dyson index.

Findings

eta topological gravity interpolates between orientable and unorientable manifolds.

Structural properties imply generalized moduli space volume relations.

Strong evidence for quantum chaos in eta topological gravity.

Abstract

We use the well established duality of topological gravity to a double scaled matrix model with the Airy spectral curve to define what we refer to as topological gravity with arbitrary Dyson index $\upbeta$ ($\upbeta$ topological gravity). On the matrix model side this is an interpolation in the Dyson index between the Wigner-Dyson universality classes, on the gravity side it can be thought of as interpolating between orientable and unorientable manifolds in the gravitational path integral, opening up the possibility to study moduli space volumes of manifolds ``in between''. Using the perturbative loop equations we study correlation functions of this theory and prove several structural properties, having clear implications for the generalised moduli space volumes. Additionally we give a geometric interpretation of these properties using the generalisation to arbitrary Dyson index of the recently found Mirzakhani-like recursion for unorientable surfaces. Using these properties, we investigate whether $\upbeta$-topological gravity is quantum chaotic in the sense of the Bohigas-Giannoni-Schmit conjecture. Along the way we answer this question for the symplectic Wigner-Dyson class, not studied in the literature yet, and establish strong evidence for quantum chaos for this version of the theory, and thus for all bosonic varieties of topological gravity. We further argue for quantum chaoticity in the general $\upbeta$ case, based on novel constraints we find to be obeyed by genuinely non-Wigner-Dyson parts of the moduli space volumes. As for the general $\upbeta$ case the universal behaviour expected from a chaotic system is not known fully analytically we give a novel way to approach it, starting with the result of $\upbeta$ topological gravity and compare the results to a numerical evaluation of the universal result.