Signatures of Quantum Chaos in the D1D5 System

TL;DR

This paper explores how quantum chaos signatures, specifically random-matrix statistics, emerge in the D1D5 conformal field theory through finite-N effects and cycle-structure mixing.

Contribution

It demonstrates that non-planar cycle mixing at finite N correlates with the appearance of level repulsion and random-matrix behavior in the D1D5 system.

Findings

Poisson-like level statistics in the large-N limit

Finite-N non-planar effects induce level repulsion

Cycle-structure mixing correlates with quantum chaos signatures

Abstract

We investigate the emergence of random-matrix statistics in the D1D5 CFT by studying second-order lifting matrices in low-energy near-BPS sectors. We compare the $N=3$ finite-$N$ lifting problems with the planar large-$N$ limit at fixed orbifold conformal weight and R charges. In the planar large-$N$ limit at fixed orbifold energy, mixing between single-cycle and multi-cycle states is suppressed, and the symmetry-resolved lifting spectra display Poisson-like level statistics. At finite $N$, non-planar terms restore this mixing between different cycle structures. Within the resulting symmetry-resolved sectors, this finite-$N$ mixing is accompanied by level repulsion consistent with random-matrix behavior. These results suggest that, in the low-energy near-BPS sectors accessible to our analysis, non-planar cycle-structure mixing at finite $N$ is associated with the onset of level repulsion and random-matrix-like spacing statistics.