# Entanglement and chaos in warped conformal field theories

## TL;DR

This paper explores entanglement, chaos, and entropy dynamics in warped conformal field theories, revealing their maximal chaos and topological entropy changes, with implications for holography and black hole physics.

## Contribution

It provides the first detailed calculations of entanglement and Renyi entropy in WCFTs, demonstrating their maximal chaos and topological entropy evolution.

## Key findings

- WCFTs are maximally chaotic, consistent with holographic black holes.
- Entanglement entropy matches finite temperature results via ensemble change.
- Renyi entropy change is topological, vanishing at early and late times.

## Abstract

Various aspects of warped conformal field theories (WCFTs) are studied including entanglement entropy on excited states, the Renyi entropy after a local quench, and out-of-time-order four-point functions. Assuming a large central charge and dominance of the vacuum block in the conformal block expansion, (i) we calculate the single-interval entanglement entropy on an excited state, matching previous finite temperature results by changing the ensemble; and (ii) we show that WCFTs are maximally chaotic, a result that is compatible with the existence of black holes in the holographic duals. Finally, we relax the aforementioned assumptions and study the time evolution of the Renyi entropy after a local quench. We find that the change in the Renyi entropy is topological, vanishing at early and late times, and nonvanishing in between only for charged states in spectrally-flowed WCFTs.