# Twistor theory
The twistor theory is a non-local reorganisation of physical information in terms of geometric data. It is therefore intrinsically holographic in a certain sense. For example, the conformal structure of spacetime is manifested as holomorphic structures of the twistor space.
## Refs
- original [[Penrose1967]]
- good for learning
- [[Rsc0053 Tim Adamo Lectures on Twistor Theory 2017]]
- [[book_HuggettTod]]
- standard reference [[book_PenroseRindler]]
- [[book_WardWells]] more mathematical
- integrability oriented: [[book_MasonWoodhouse]] and [[book_Dunakski]]
- review [[review_MacCallumPenrose1972]]
- useful intro
- recent historic overview [[AtiyahDunajskiMason2017]]
- for CCFT
- [[2022#Bu, Casali]] etc
- [[0421 Higher-spin gravity|higher spin]]
- for chiral higher-spin gravity in AdS: [[Tran202209]][](https://arxiv.org/pdf/2209.00925.pdf)
- review [[Tran202211Lectures]][](https://arxiv.org/pdf/2211.10484.pdf)
- in dS or AdS
- [[2024#Baumann, Mathys, Pimentel, Rost]]
## Twistor space
- the twistor space, $\mathbb{P}\mathbb{T}$, is an open subset of $\mathbb{C}\mathbb{P}^3$
- $Z^I\sim sZ^I$, $s$ being complex
- $Z^I=\left(\mu^{\dot{\alpha}}, \lambda_\alpha\right)$
- the complex line $\lambda=0$ is removed
- relation to spacetime coordinates, known as the *incidence relation*
- $\mu^{\dot{\alpha}}=x^{\dot{\alpha} \alpha} \lambda_\alpha$
## Applications
- [[Witten200312]][](https://arxiv.org/abs/hep-th/0312171)
- resurrection of twistors
- combines string perturbation theory to calculate the entire tree-level S-matrix of YM in 4D
## Signature dependence
The number of degrees of freedoms of the twistors depend on the dimension and signature of the spacetime. In [[0056 Split signature|split signature]] (2,2), the spinors are real and independent.