Quantum aspects of charged black holes in de-Sitter space

Abstract: It has been argued that generic classical perturbations to asymptotically de-Sitter Reissner-Nordtsr\"om (RN-dS) black holes may violate strong cosmic censorship conjecture. In this paper, we analyze whether quantum corrections can restore the conjecture. We study a quantum scalar field in RN-dS geometry and analyze the smoothness of a state across various horizons using the criteria developed in arXiv:1910.02992. Since de-Sitter black holes have a cosmological horizon, that typically radiates at a different temperature than the event horizon, the existence of a quantum state which is regular everywhere in the exterior region is non-trivial. We find such states for spherically symmetric black holes in arbitrary dimensions. We then demonstrate that such states are singular at the inner horizon of RN-dS black holes in various dimensions. Hence, quantum fluctuations are sufficient to restore the strong cosmic censorship conjecture in RN-dS.