A bstract We provide a concrete and computable realization of the ER = EPR conjecture, by deriving the Einstein-Rosen bridge from the quantum entanglement in the thermofield double CFT. The Bekenstein-Hawking entropy of the wormhole is explicitly identified as an entanglement entropy between subsystems of the thermofield double state. Furthermore, our results provide a quantitative verification of Van Raamsdonk’s conjecture about spacetime emergence.
A bstract We provide a concrete and computable realization of the ER = EPR conjecture, by deriving the Einstein-Rosen bridge from the quantum entanglement in the thermofield double CFT. The Bekenstein-Hawking entropy of the wormhole is explicitly identified as an entanglement entropy between subsystems of the thermofield double state. Furthermore, our results provide a quantitative verification of Van Raamsdonk’s conjecture about spacetime emergence.
[This is a creative exploration of a concept with AI -it should not be taken as correct mathematics.] We present a detailed examination of the conjectured correspondence between Einstein-Rosen (ER) bridges and Einstein-Podolsky-Rosen (EPR) entanglement, denoted as ER=EPR. This examination concentrates on the quantitative structures and derivations supporting this correspondence, primarily within the setting of the Anti-de Sitter/Conformal Field Theory (AdS/CFT) duality. We analyze the realization of this correspondence in the eternal black hole geometry and its dual Thermofield Double (TFD) state. A complete exposition of the holographic entanglement entropy prescriptions is provided, including the derivation of the Quantum Extremal Surface (QES) prescription via the Lewkowycz-Maldacena argument concerning the gravitational path integral and conical singularities, and the subsequent derivation of the Jafferis-Lewkowycz-Maldacena-Suh (JLMS) relation establishing the equality of bulk and boundary relative entropies. We investigate the relationship between the temporal evolution of the spacetime geometry, characterized by the growth of the Einstein-Rosen bridge, and the evolution of quantum complexity. A complete derivation of the maximal volume growth rate is provided, carefully analyzing the geometry inside the horizon. Furthermore, a complete derivation of the action growth rate, supporting the Complexity=Action conjecture, is provided, clarifying the precise contribution of bulk, boundary, and joint terms in the gravitational action according to the definitions established by Lehner et al. for manifolds with null boundaries. The correspondence is extended to typical entangled states, characterized by Einstein-Rosen caterpillars. We derive the effective Hamiltonian governing the ensemble average of the generating random circuits and establish the quantitative relationship between the geometric length of the wormhole and the measure of quantum randomness (k-designs), utilizing the results of Magán, Sasieta, and Swingle. The role of QES and the derivation of the Page curve via replica wormholes are analyzed, detailing the calculations in Jackiw-Teitelboim gravity theories following Penington et al. Mechanisms for rendering wormholes traversable via boundary interactions (Gao-Jafferis-Wall construction) and operational interpretations based on Local Operationsand Classical Communication protocols are also discussed, emphasizing the quantitative consistency of these interconnected concepts.
An accumulation of theoretical evidence contribute to the picture of gravity as a manifestation of quantum entanglement in a certain many-body quantum system. This is in particular expresses in the ER=EPR conjecture, which relates gravitational Einstein-Rosen (ER) bridge with the Einstein-Podolsky-Rosen (EPR) quantum entangled pairs or, more generally, with the so-called Thermofield Double State. In this letter, the ER=EPR conjecture is employed to introduce unitary quantum teleportation protocol, which \emph{recycles} the entanglement forming traversable generalization of the Einstein-Rosen bridge. In consequence, the wormhole remains unaffected by the quantum teleportation. Furthermore, it is shown that the protocol guarantees the unconditional security of the quantum communication. Performance of the protocol is demonstrated in a simple setting with the use of 5-qubit Santiago IBM quantum computer, giving fidelities above the 2/3 classical limit for a representative set of teleported states. Security of the protocol has been supported by experimental studies performed with the use of the noisy quantum processor. Possible generalization of the protocol, which may have relevance in the context of macroscopic gravitational configurations, is also considered.
If spacetime is built out of quantum bits, does the shape of space depend on how the bits are entangled? The ER=EPR conjecture relates the entanglement entropy of a collection of black holes to the cross sectional area of Einstein-Rosen (ER) bridges (or wormholes) connecting them. We show that the geometrical entropy of classical ER bridges satisfies the subadditivity, triangle, strong subadditivity, and Cadney-Linden-Winter inequalities. These are nontrivial properties of entanglement entropy, so this is evidence for ER=EPR. We further show that the entanglement entropy associated with classical ER bridges has nonpositive tripartite information. This is not a property of entanglement entropy, in general. For example, the entangled four qubit pure state ∣GHZ4⟩=(∣0000⟩+∣1111⟩)/2 has positive tripartite information, so this state cannot be described by a classical ER bridge. Large black holes with massive amounts of entanglement between them can fail to have a classical ER bridge if they are built out of ∣GHZ4⟩ states. States with nonpositive tripartite information are called monogamous. We conclude that classical ER bridges require monogamous EPR correlations.
This preprint offers a minimal, background-independent logical re-reading of the ER=EPR conjecture using the Logical Language (LL) of standard quantum mechanics. ER=EPR links quantum entanglement to geometric connections (Einstein–Rosen bridges) in emergent spacetime, with standard arguments relying on AdS/CFT and the Ryu–Takayanagi formula. LL strictly follows textbook QM and classical logic, defining physical existence solely by in-principle distinguishability (a detector). Undefined classical local spacetime variables across regions thus lack independent reality. Consistency then requires stronger-than-classical correlations to maintain connectivity, yielding the simple relation: the closer two points, the stronger the correlation. This captures ER=EPR’s core intuition (entanglement as geometric proximity) with far fewer assumptions—no duality, no holographic background, no new postulates—using only standard QM. The note recaps LL (definitional existence, operating setups), illustrates via double-slit and EPR examples, and derives the correlation–distance link from two premises (Consistency and Definitional Existence).
We calculate the topological entanglement entropy (TEE) in Euclidean asymptotic AdS3 spacetime using surgery. The treatment is intrinsically three-dimensional. In the BTZ black hole background, several different bipartitions are applied. For the bipartition along the horizon between two single-sided black holes, TEE is exactly the Bekenstein-Hawking entropy, which supports the ER=EPR conjecture in the Euclidean case. For other bipartitions, we derive an Entangling-Thermal relation for each single-sided black hole, which is of topological origin. After summing over genus-one classical geometries, we compute TEE in the high-temperature regime. In the case where k = 1, we find that TEE is the same as that for the Moonshine double state, given by the maximally-entangled superposition of 194 types of “anyons” in the 3d bulk, labeled by the irreducible representations of the Monster group. We propose this as the bulk analogue of the thermofield double state in the Euclidean spacetime. Comparing the TEEs between thermal AdS3 and BTZ solutions, we discuss the implication of TEE on the Hawking-Page transition in 3d.
This paper illustrates various aspects of the ER=EPR conjecture. It begins with a brief heuristic argument, using the Ryu‐Takayanagi correspondence, for why entanglement between black holes implies the existence of Einstein‐Rosen bridges. The main part of the paper addresses a fundamental question: Is ER=EPR consistent with the standard postulates of quantum mechanics? Naively it seems to lead to an inconsistency between observations made on entangled systems by different observers. The resolution of the paradox lies in the properties of multiple black holes, entangled in the Greenberger‐Horne‐Zeilinger pattern. The last part of the paper is about entanglement as a resource for quantum communication. ER=EPR provides a way to visualize protocols like quantum teleportation. In some sense teleportation takes place through the wormhole, but as usual, classical communication is necessary to complete the protocol.