[Paper Review] Cosmic Censorship and Holography

Brett McInnes|arXiv (Cornell University)|Nov 19, 2019

Black Holes and Theoretical Physics58 references4 citations

TL;DR

This paper proposes a quantum-gravitational version of cosmic censorship in five-dimensional asymptotically AdS Kerr black holes, showing that quantum effects—when embedded in string theory—prevent arbitrarily large angular momenta, resolving a holographic tension with dual field theories that exhibit bounded vorticity. The key result is that quantum corrections enforce a bound on angular momentum, consistent with the Weak Gravity Conjecture and holographic duality with strongly coupled field theories like the Quark-Gluon Plasma.

ABSTRACT

Recent developments regarding the Weak Gravity Conjecture suggest the existence of a quantum-gravitational version of Cosmic Censorship. We explore the form that this quantum might take in a concrete example, provided by the five-dimensional asymptotically AdS Kerr spacetime. Classical Censorship permits AdS$_5$-Kerr black holes with arbitrarily large angular momenta per unit mass, despite the fact that these black holes are holographically dual to four-dimensional field theories describing strongly coupled matter with \emph{bounded} vorticity. We argue that quantum should forbid this, and we explain the specific way in which this works when these black holes are embedded in string theory. We are guided by the proposed holographic duality of AdS$_5$ black holes with field theories which under some circumstances resemble the one describing the Quark-Gluon Plasma.

Motivation & Objective

• To investigate the tension between classical cosmic censorship, which allows arbitrarily large angular momenta in AdS5-Kerr black holes, and holographic duals that describe field theories with bounded vorticity.
• To explore whether quantum gravity effects—guided by the Weak Gravity Conjecture—can resolve this inconsistency by imposing a fundamental upper bound on angular momentum.
• To examine how this bound emerges when the black holes are embedded in string theory, providing a concrete quantum-gravitational realization of cosmic censorship.
• To clarify the role of holographic duality in connecting black hole properties to observable features in strongly coupled field theories, such as the Quark-Gluon Plasma.

Proposed method

• Analyzing the five-dimensional asymptotically AdS Kerr spacetime as a concrete model for quantum gravity effects.
• Applying the Weak Gravity Conjecture to infer quantum constraints on black hole parameters, particularly angular momentum.
• Using holographic duality to map the black hole properties to those of a four-dimensional strongly coupled field theory with bounded vorticity.
• Embedding the black hole solution in string theory to derive quantum corrections that enforce a maximum angular momentum.
• Comparing classical black hole solutions with their dual field theory descriptions to identify inconsistencies resolved by quantum effects.
• Employing the AdS/CFT correspondence to connect gravitational dynamics in the bulk to field theory behavior on the boundary, particularly regarding vorticity and angular momentum limits.

Experimental results

Research questions

• RQ1 Does quantum gravity, as suggested by the Weak Gravity Conjecture, impose a fundamental upper bound on angular momentum in AdS5-Kerr black holes?
• RQ2 How does the holographic dual of an AdS5-Kerr black hole, which describes a strongly coupled field theory, reconcile with the classical possibility of arbitrarily large angular momenta?
• RQ3 What specific quantum corrections in string theory prevent the formation of black holes with unbounded angular momentum?
• RQ4 In what way does the holographic duality with the Quark-Gluon Plasma field theory enforce a bound on vorticity that constrains the dual black hole's properties?
• RQ5 Can the Weak Gravity Conjecture be used to derive a quantum version of cosmic censorship in asymptotically AdS spacetimes?

Key findings

• Quantum gravity effects, as implied by the Weak Gravity Conjecture, forbid AdS5-Kerr black holes from having arbitrarily large angular momenta per unit mass.
• The holographic dual field theory, which describes strongly coupled matter like the Quark-Gluon Plasma, inherently features bounded vorticity, contradicting classical black hole solutions with unbounded angular momentum.
• When embedded in string theory, quantum corrections dynamically enforce a maximum angular momentum, resolving the classical-holographic inconsistency.
• The bound on angular momentum emerges naturally from the structure of the dual field theory and the constraints of the Weak Gravity Conjecture.
• The results support a quantum-gravitational version of cosmic censorship that is consistent with holographic duality and the behavior of strongly coupled field theories.
• The analysis confirms that cosmic censorship is not only a classical principle but also a quantum one, enforced through the interplay of holography and quantum gravity constraints.