# Comments on Holographic Entanglement Entropy in TT Deformed CFTs

## TL;DR

This paper refines the understanding of the Ryu-Takayanagi formula's applicability in TT deformed holographic theories, clarifying theoretical subtleties and implications for holography beyond pure AdS spaces.

## Contribution

It provides a detailed justification for using the RT formula in TT deformed theories and discusses related holographic counterterms and spacetime implications.

## Key findings

- RT formula remains valid in TT deformed holographic theories
- Clarification of counterterm subtleties in holography
- Implications for holography in general spacetimes

## Abstract

The Ryu-Takayanagi (RT) formula has been a key ingredient in our understanding of holography. Recent work on TT deformations has also boosted our understanding of holography away from the conformal boundary of AdS. In this short note, we aim to refine some recent work demonstrating the success of the RT formula in TT deformed theories. We emphasize general arguments that justify the use of the RT formula in general holographic theories that obey a GKPW-like dictionary. In doing so, we clarify subtleties related to holographic counterterms and discuss the implications for holography in general spacetimes.