The Baby Universe is Fine and the CFT Knows It: On Holography for Closed Universes

• URL: http://arxiv.org/abs/2507.10649v1
• Date: Mon, 14 Jul 2025 18:00:00 GMT
• Title: The Baby Universe is Fine and the CFT Knows It: On Holography for Closed Universes
• Authors: Stefano Antonini, Pratik Rath, Martin Sasieta, Brian Swingle, Alejandro Vilar López,
• Abstract summary: We show that big bang/big crunch closed universes can be realized in AdS/CFT.<n>With enough bulk entanglement, the bulk Hilbert space of a closed universe can be holographically encoded in the CFT.<n>We propose a model of the emergence of an arrow of time in the universe with a given initial or final state projection.
• Score: 39.58317527488534
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Big bang/big crunch closed universes can be realized in AdS/CFT, even though they lack asymptotically AdS boundaries. With enough bulk entanglement, the bulk Hilbert space of a closed universe can be holographically encoded in the CFT. We clarify the relation of this encoding to observer-clone proposals and refute recent arguments about the breakdown of semiclassical physics in such spaces. In the limit of no bulk entanglement, the holographic encoding breaks down. The oft-cited one-dimensional nature of the closed universe Hilbert space represents the limitation of the external (CFT) Hilbert space to access the quantum information in the closed universe, similar to the limitations imposed on observers outside a perfectly isolated quantum lab. We advocate that the CFT nevertheless continues to determine the physical properties of the closed universe in this regime, showing how to interpret this relationship in terms of a final state projection in the closed universe. We provide a dictionary between the final state wavefunction and CFT data. We propose a model of the emergence of an arrow of time in the universe with a given initial or final state projection. Finally, we show that the conventional EFT in the closed universe, without any projection, can be recovered as a maximally ignorant description of the final state. This conventional EFT is encoded in CFT data, and it can be probed by computing coarse-grained observables. We provide an example of one such observable. Taken together, these results amount to a clean bill of health for baby universes born of AdS/CFT.

Related papers

• Horizon quantum geometries and decoherence [49.1574468325115]
  There is mounting theoretical evidence that black hole horizons induce decoherence on a quantum system.<n>This phenomenon has been shown to owe its existence to soft modes.<n>We show that the discreteness of the energy levels associated to the different geometric configurations might have strong impact on the results.
  arXiv  Detail & Related papers  (2025-07-24T18:00:30Z)
• Temporal Entanglement from Holographic Entanglement Entropy [44.99833362998488]
  We propose a systematic prescription to characterize temporal entanglement in quantum field theory.<n>For holographic quantum field theories, our prescription amounts to an analytic continuation of all co-dimension-two bulk extremal surfaces.<n>We show that it leads to results with self-consistent physical properties of temporal entanglement.
  arXiv  Detail & Related papers  (2025-07-23T18:14:21Z)
• Synthetic multi-dimensional Aharonov-Bohm cages in Fock state lattices [15.974000822739983]
  We demonstrate the construction of multi-dimensional FSLs using superconducting quantum circuits.<n>We explore the coherent interference of quantum superposition states, achieving extreme localization within specific subspaces.<n>Our findings pave the way for manipulating the behavior of a broad class of quantum states in higher-dimensional systems.
  arXiv  Detail & Related papers  (2024-12-13T00:13:43Z)
• Maximal steered coherence in the background of Schwarzschild space-time [9.092982651471674]
  We find that as the Hawking temperature increases, the physically accessible MSC degrades while the unaccessible MSC increases. Our findings illuminate the intricate dynamics of quantum information in the vicinity of black holes.
  arXiv  Detail & Related papers  (2024-08-22T13:40:33Z)
• Semi-Classical Subspaces, The No Synchronization Law, and More [6.5268245109828005]
  This paper looks at the intersection of algorithmic information theory and physics. We discuss theorems which characterize the barrier between the quantum world and the classical realm. We look at future work involving the Kolmogorov complexity of black holes.
  arXiv  Detail & Related papers  (2024-07-25T17:09:26Z)
• Continuous percolation in a Hilbert space for a large system of qubits [58.720142291102135]
  The percolation transition is defined through the appearance of the infinite cluster. We show that the exponentially increasing dimensionality of the Hilbert space makes its covering by finite-size hyperspheres inefficient. Our approach to the percolation transition in compact metric spaces may prove useful for its rigorous treatment in other contexts.
  arXiv  Detail & Related papers  (2022-10-15T13:53:21Z)
• Surprising Spectral Gap and Entropy Decay Estimates in Open Quantum Systems with a Large Number of Qubits [6.680567488352617]
  We study the spectral gap and modified logarithmic Sobolev constant of some very simple open systems given by a representation of $mathfraksu(2)$ on N-qubits. Our examples fall into the class of Lindbladians admissible to the dissipative quantum Church-Turing thesis arXiv:1105.3986.
  arXiv  Detail & Related papers  (2022-09-22T15:36:47Z)
• Breakdown of quantum mechanics in gravitational holography [0.0]
  Black hole complementarity is inevitably linked to holography and states that information associated with the collapsed pure state is reflected in the near horizon region. We argue that the information preserving quantum atmosphere of the black hole emerges from hidden variables on its horizon. In AdS/CFT, this would mean that the completion of the semiclassical subalgebra to the complete boundary algebra has to be traced back to the emergent near horizon space structure.
  arXiv  Detail & Related papers  (2022-08-01T17:52:29Z)
• A New Look at the $C^{0}$-formulation of the Strong Cosmic Censorship Conjecture [68.8204255655161]
  We argue that for generic black hole parameters as initial conditions for Einstein equations, the metric is $C0$-extendable to a larger Lorentzian manifold. We prove it violates the "complexity=volume" conjecture for a low-temperature hyperbolic AdS$_d+1$ black hole dual to a CFT living on a ($d-1$)-dimensional hyperboloid $H_d-1$.
  arXiv  Detail & Related papers  (2022-06-17T12:14:33Z)
• Weyl Curvature Hypothesis in light of Quantum Backreaction at Cosmological Singularities or Bounces [0.0]
  Penrose's 1979 Weyl curvature hypothesis (WCH) assumes that the universe began at a very low gravitational entropy state. In classical general relativity the most general cosmological solutions of the equation Einstein are that of the BKL-Misner inhomogeneous mixmaster types. Backreaction effects of quantum field processes probably serve as the best guarantor of WCH.
  arXiv  Detail & Related papers  (2021-10-03T21:22:08Z)
• Bell's Theorem, Non-Computability and Conformal Cyclic Cosmology: A Top-Down Approach to Quantum Gravity [0.0]
  In IST, the fundamental laws of physics describe the geometry of the phase portrait of the universe as a whole. It becomes possible to explain the experimental violation of Bell Inequalities without having to abandon key ingredients of general relativity.
  arXiv  Detail & Related papers  (2021-08-24T18:12:16Z)
• Generalized Probabilistic Theories in a New Light [0.0]
  A new answer to the question of why our universe is quantum mechanical rather than classical will be presented. This paper shows that there is still a possibility that there might be a deterministic level from which our universe emerges.
  arXiv  Detail & Related papers  (2021-03-08T21:28:19Z)
• Bounding the finite-size error of quantum many-body dynamics simulations [6.657101721138396]
  We derive rigorous upper bounds on the Finite-size error (FSE) of local observables in real time quantum dynamics simulations from a product state. Our bounds are practically useful in determining the validity of finite-size results, as we demonstrate in simulations of the one-dimensional (1D) quantum Ising and Fermi-Hubbard models.
  arXiv  Detail & Related papers  (2020-09-25T04:30:25Z)
• CPT Symmetry in Projective de Sitter Universes [0.0]
  In a recent work, Boyle, Finn and Turok hypothesized a model of universe that does not violate the CPT-symmetry as alternative for inflation. Here we examine the validity of this proposal by adopting the point of view of archaic cosmology. In this scenario, the big bang is caused by the instability of the original (pre)vacuum with respect to the nucleation of micro-events.
  arXiv  Detail & Related papers  (2020-02-18T13:36:35Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.