>[!warning]
>This content has not been peer reviewed.
# Ryu–Takayanagi Metric — RST application
The RT formula is a concrete case where **entanglement determines geometry**.
RST uses this as an engine design rule: define an **effective distance**
directly from an entanglement / coherence proxy, and let the simulation’s
connectivity update that distance dynamically.
This folder provides a runnable toy implementation: maintain \(E_{ij}\) and
define \(d_{ij} = -\log(E_{ij} + \epsilon)\); update \(E_{ij}\) upward when
nodes share coherent workload and let it decay otherwise.
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## I. Mapping to RST
| Classical concept | RST reading |
|:---|:---|
| Entanglement entropy ↔ area | Connectivity / coherence ↔ distance / “metric”. |
| Minimal surface | Least-cost coupling surface (operational proxy). |
| Geometry from entanglement | Engine distance derived from shared workload. |
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## II. Script and verification
- Script: **[[Ryu-Takayanagi Metric - Code]]** (`rst_rt_metric_entanglement_distance.py`)
- Output: `rt_metric_entanglement_distance.png`
- Result note: **[[Ryu-Takayanagi Metric Results]]**