dS_4$ universe emergent from Kerr-AdS_5$ spacetime: bubble nucleation catalyzed by a black hole

• Main Authors: Koga, Issei, Oshita, Naritaka, Ueda, Kazushige
• Format: Journal Article
• Language: English
• Published: 12.09.2022
• Subjects: Physics - General Relativity and Quantum Cosmology; Physics - High Energy Physics - Theory
• DOI: 10.48550/arxiv.2209.05625

JHEP05(2023)107 The emergence of a four-dimensional de Sitter (dS_4$) universe on an expanding bubble in the five-dimensional anti-de Sitter (AdS_5$) background has been suggested as a possible cosmological scenario. It is motivated by the difficulties in the realization of a stable de Sitter vacua in string theory. The bubble can be nucleated in a meta-stable pure AdS_5$ spacetime, but it is known that a pure AdS spacetime is non-perturbatively unstable. It means that the pure AdS_5$ background is an idealized situation, and in realistic situations, non-linear perturbations in AdS may lead to the formation of black holes due to the gravitational turbulent instability. To investigate how the proposed scenario works in a more realistic situation, we here study the nucleation process of a vacuum bubble in the Kerr-AdS_5$ spacetime. Especially we investigate conditions sufficient to ensure the nucleation of a vacuum bubble with a rotating black hole and how the black hole affects the transition rate. We find that even in the Kerr-AdS_5$ spacetime, a quasi-dS_4$ expansion can be realized on the nucleated vacuum bubble without contradicting the de Sitter swampland conjectures.