Hadamard state in Schwarzschild-de Sitter spacetime

Understand

We construct a state in the Schwarzschild-de Sitter spacetime which is invariant under the action of its group of symmetries.

• Our state is not defined in the whole Kruskal extension of this spacetime, but rather in a subset of the maximally extended conformal diagram.
• The construction is based on a careful use of the bulk-to-boundary technique.
• We will show that our state is Hadamard and that it is not a KMS state, differently from the case of states constructed in spacetimes containing only one event horizon.