# Bit thread
Bit threads are proposed as an alternative way to describe the bulk [[0007 RT surface|RT surface]] that tries to make manifest the underlying physical mechanisms of entanglement *in the bulk*.
## Extensions
- Lorentzian
- [[2021#Pedraza, Russo, Svesko, Weller-Davies]]
- [[2022#Headrick, Hubeny]]: covariant
- quantum
- [[Rolph2021]][](https://arxiv.org/pdf/2105.08072.pdf)
- [[2021#Agon, Pedraza]]
- [[0006 Higher-derivative gravity|higher-derivative gravity]]
- [[HarperHeadrickRolph2018]][](https://arxiv.org/pdf/1807.04294.pdf)
- general spacetime
- [[2024#Du, Sun]]
- relation to [[0292 Partial entanglement entropy|partial entanglement entropy]]
- [[2021#Lin, Sun, Zhang]]