Islands in Kerr-de Sitter spacetime and their flat limit

Understand

We use quantum extremal island method to study the information paradox on certain cosmological setups known as three dimensional Kerr-de Sitter spacetimes.

• To do so, we couple an auxiliary flat bath system to this spacetime in timelike singularity and measure entropy of hawking radiation in its asymptotic regions where the gravity is weak.
• We show that adding island regions to the entanglement wedge of radiation causes its entropy to obey Page curve.
• The boundary of island i.e.