Relating chronology protection and unitarity through holography

Understand

We give a simple nonsupersymmetric example in which chronology protection follows from unitarity and the AdS/CFT correspondence.

• We consider a ball of homogeneous, rotating dust in global AdS3 whose backreaction produces a region of Goedel space inside the ball.
• We solve the Israel matching conditions to find the geometry outside of the dust ball and compute its quantum numbers in the dual CFT.
• When the radius of the dust ball exceeds a certain critical value, the spacetime will contain closed timelike curves.