Cool horizons for entangled black holes (1306.0533v2)

Abstract: General relativity contains solutions in which two distant black holes are connected through the interior via a wormhole, or Einstein-Rosen bridge. These solutions can be interpreted as maximally entangled states of two black holes that form a complex EPR pair. We suggest that similar bridges might be present for more general entangled states. In the case of entangled black holes one can formulate versions of the AMPS(S) paradoxes and resolve them. This suggests possible resolutions of the firewall paradoxes for more general situations.

• The paper introduces the ER=EPR conjecture connecting quantum entanglement with non-traversable wormholes between black holes.
• It analyzes how entanglement influences black hole entropy and addresses the firewall paradox.
• The study offers fresh insights into unifying quantum mechanics with general relativity and advancing quantum gravity theory.

Cool Horizons for Entangled Black Holes

The paper "Cool Horizons for Entangled Black Holes" by Juan Maldacena and Leonard Susskind proposes a conjecture denoted as "ER=EPR", linking two formerly distinct concepts in theoretical physics: Einstein-Rosen bridges (ER), or wormholes, and Einstein-Podolsky-Rosen (EPR) correlations, which are a demonstration of quantum entanglement. The authors suggest that these two ideas might be connected, asserting that any pair of entangled particles could similarly be connected through a non-traversable wormhole.

Conceptual Background

The authors begin by discussing solutions found in general relativity where two distanced black holes can be linked internally through a wormhole. These configurations not only retain the traditional characteristics associated with Einstein-Rosen bridges but also can act as maximally entangled states of two black holes. This subsequently leads to the consideration of possible implications for resolving prominent paradoxes in theoretical physics, such as the AMPS (Almheiri-Marolf-Polchinski-Sully) paradoxes, by suggesting that resolving the paradoxes might reshape our understanding of spacetime mechanics and quantum entanglement.

Core Ideas

1. ER=EPR Conjecture: The core argument is that if quantum systems are entangled, a geometric connection—an Einstein-Rosen bridge—might join them in a way not violating any known laws of physics, although these bridges are not traversable due to the impossibility of signal transfer exceeding the speed of light.
2. Einstein-Rosen Bridges and Entropy: The paper investigates the entropy linked to black holes, notably how entangled black holes can exchange information through their interiors via non-traversable wormholes. This could redefine the classical view of black hole entropy and the entangled nature of Hawking Radiation.
3. Resolving Paradoxes: The authors propose that incorporating the ER=EPR concept can address the firewall paradox, which suggests information falling into a black hole might encounter a "firewall" at the event horizon. If wormholes in the form of entanglement provide smooth interiors, it might prevent hypothetical firewalls, thus maintaining the smooth entry into a black hole.
4. Practical Implications: From a practical viewpoint, this could create new possibilities for theoretical experiments. For instance, connecting two black holes via a non-traversable wormhole where entanglement is manipulated offers profound implications for designing theories that unite quantum mechanics with general relativity.
5. Speculations on Quantum Gravity: By postulating that entanglement is a form of spacetime connectivity, this theory presents surprising conjectures about quantum gravity, suggesting that spacetime geometry might be intricately constructed or influenced by the entanglement of its quantum constituents.
6. Computational Implications in Quantum Mechanics: Understanding the vast complexities and intertwining of entangled quantum states has expansive implications for quantum computing, possibly paving a new path for decoding and safeguarding quantum information.

Theoretical Implications

The ideas put forth in this paper prompt further theoretical ventures into understanding black hole interiors, quantum entanglement, and overall spacetime geometry. They highlight crucial dialogues about the intrinsic connectedness of particles irrespective of classical separator—the fabric of spacetime itself might be an expression of quantum states’ entanglements.

Future Prospects

From a future perspective, unraveling these conceptions could initiate essential discussions in speculative physics on the nature and behavior of quantum mechanics in grand unifying theories and exploring minute intricacies of quantum gravity.

Overall, this paper provides significant theoretical interplay across the fields of quantum mechanics and general relativity, sparking intriguing questions about the invisible threads stitching our universe together and setting a foundation for future explorations into the quantum structure of space and time.