Holographic entanglement entropy, Wilson loops, and neural networks

Abstract

We apply artificial neural networks to the holographic inverse problem, reconstructing bulk geometry from boundary entanglement entropy by using the Ryu--Takayanagi area functional as a differentiable loss. Validated on the AdS-Schwarzschild background, this approach recovers the blackening factor with maximum absolute error below $3\times10^{-3}$ across the entire bulk, reproducibly over independent training runs. For finite-density backgrounds like the Gubser--Rocha model, we demonstrate that equal-time strip entanglement entropy determines only the spatial metric. We resolve this exact one-function degeneracy by incorporating holographic Wilson loop data, which couples to the timelike metric. We present a semi-analytical inversion combining Bilson's and Hashimoto's formulas, alongside a general three-network variational method minimizing the combined area and Nambu--Goto actions. The neural network achieves maximum relative errors below $0.2\%$ for both metric functions without closed-form derivative relations, and accommodates additional holographic observables at the cost of one extra network and loss term.