Binary Black Hole Information Loss Paradox and Future Prospects

AIP Conference Proceedings, 2009

The gravity-scalar field system in spherical symmetry provides a natural setting for exploring gravitational collapse and its aftermath in quantum gravity. In a canonical approach, we give constructions of the constraint and Hamiltonian operators. Matter-gravity entanglement is an inherent feature of physical states, whether or not there is a black hole. Matter fields alone are an open system with a non-unitary evolution. However, if there is a successful theory of quantum gravity, there is no information loss.

The black-hole information paradox has fueled a fascinating effort to reconcile the predictions of general relativity and those of quantum mechanics. Gravitational considerations teach us that black holes must trap everything that falls into them. Quantum mechanically the mass of a black hole leaks away as featureless (Hawking) radiation. However, if Hawking's analysis turned out to be accurate then the information would be irretrievably lost and a fundamental axiom of quantum mechanics, that of unitary evolution, would likewise fail. Here we show that the information about the matter that collapses to form a black hole becomes encoded into pure correlations within a tripartite quantum system, the quantum analog of a one-time pad until very late in the evaporation, provided we accept the view that the thermodynamic entropy of a black hole is due to entropy of entanglement. In this view the black hole entropy is primarily due to trans-event horizon entanglement between external m...

Physical Review Letters, 2007

Can quantum-information theory shed light on black-hole evaporation? By entangling the in-fallen matter with an external system we show that the black-hole information paradox becomes more severe, even for cosmologically sized black holes. We rule out the possibility that the information about the infallen matter might hide in correlations between the Hawking radiation and the internal states of the black hole. As a consequence, either unitarity or Hawking's semiclassical predictions must break down. Any resolution of the black-hole information crisis must elucidate one of these possibilities.

arXiv (Cornell University), 2014

We propose a combination of two mechanisms that can resolve the black hole information paradox. The first process is that the black hole shrinks by a first order transition, since we assume the entropy is discontinuous. The black hole disappears. The second type of processes conserves unitarity. We assume that within the black hole micro-reversible quantum mechanical processes take place. These are ordinary particle processes, e.g. the decay of an electron and a positron into two photons.

Astronomische Nachrichten, 2003

A possible link between EPR-type quantum phenomena and astrophysical objects like black holes, under a new general definition of entanglement, is established. A new approach, involving backward time evolution and topology changes, is presented bringing to a definition of the system black hole-worm hole-white hole as an entangled system.

Physical Review D, 1995

We analyze a system consisting of an oscillator coupled to a field. With the field traced out as an environment, the oscillator loses coherence on a very short decoherence timescale; but, on a much longer relaxation timescale, predictably evolves into a unique, pure (ground) state. This example of recoherence has interesting implications both for the interpretation of quantum theory and for the loss of information during black hole evaporation. We examine these implications by investigating the intermediate and final states of the quantum field, treated as an open system coupled to an unobserved oscillator.

ResearchGate, 2024

This paper explores the possibility of retrieving information from black holes by leveraging quantum entanglement properties. By extending previous work on extended quantum state normalization and cosmological models, we hypothesize that information entangled within black holes can be accessed through their interconnected nested structures. We synthesize theoretical models and recent research to provide a comprehensive framework for these phenomena, potentially revolutionizing quantum communication and computing across cosmic scales. Our approach integrates concepts from Banach space formalism, Hilbert space fragmentation, and the ruliad to propose novel methods for quantum information processing using cosmic-scale quantum effects.

A coarse-grained description for the formation and evaporation of a black hole is given within the framework of a unitary theory of quantum gravity preserving locality, without dropping the information that manifests as macroscopic properties of the state at late times. The resulting picture depends strongly on the reference frame one chooses to describe the process. In one description based on a reference frame in which the reference point stays outside the black hole horizon for sufficiently long time, a late black hole state becomes a superposition of black holes in different locations and with different spins, even if the back hole is formed from collapsing matter that had a well-defined classical configuration with no angular momentum. The information about the initial state is partly encoded in relative coefficients---especially phases---of the terms representing macroscopically different geometries. In another description in which the reference point enters into the black hole horizon at late times, an S-matrix description in the asymptotically Minkowski spacetime is not applicable, but it sill allows for an "S-matrix" description in the full quantum gravitational Hilbert space including singularity states. Relations between different descriptions are given by unitary transformations acting on the full Hilbert space, and they in general involve superpositions of "distant" and "infalling" descriptions. Despite the intrinsically quantum mechanical nature of the black hole state, measurements performed by a classical physical observer are consistent with those implied by general relativity. In particular, the recently-considered firewall phenomenon can occur only for an exponentially fine-tuned (and intrinsically quantum mechanical) initial state, analogous to an entropy decreasing process in a system with large degrees of freedom.

The fate of classical information incident on a quantum black hole has been the subject of an ongoing controversy in theoretical physics, because a calculation within the framework of semi-classical curved-space quantum field theory appears to show that the incident information is irretrievably lost, in contradiction to time-honored principles such as time-reversibility and unitarity. Here, we show within this framework embedded in quantum communication theory that signaling from past to future null infinity in the presence of a Schwarzschild black hole can occur with arbitrary accuracy, and thus that classical information is not lost in black hole dynamics. The calculation relies on a treatment that is manifestly unitary from the outset, where probability conservation is guaranteed because black holes stimulate the emission of radiation in response to infalling matter. This stimulated radiation is non-thermal and contains all of the information about the infalling matter, while Hawking radiation contains none of it.

Classical and Quantum Gravity, 2012

We give a review of the black-hole/qubit correspondence that incorporates not only the earlier results on black hole entropy and entanglement measures, seven qubits and the Fano plane, wrapped branes as qubits and the attractor mechanism as a distillation procedure, but also newer material including error-correcting codes, Mermin squares, Freudenthal triples and 4-qubit entanglement classification.