Black Hole Information Research Articles

Jackiw-Teitelboim gravity as a noncritical string

Jackiw Teitelboim (JT) gravity has proven to be an excellent tool for investigating aspects of quantum gravity and black hole physics. In recent years, the study of JT gravity and its deformations has helped us learn about the different contributions of geometries in the gravitational path integral, the quantum gravity Hilbert space, the space-time factorization problem, the role of averaging in holography, the black hole information paradox, and the matrix models. All this motivates the exploration of the JT gravity in different setups, with and without matter. Here, we consider JT gravity conformally coupled to Liouville field theory and matter fields. This model admits to be interpreted as a noncritical string theory on a linear dilaton background with a tachyonic Liouville potential along a null direction. The constant curvature constraint of JT gravity results in a neutralization of the Liouville mode, which makes it possible to compute the four-point correlation function of the theory analytically. Here we give the explicit derivation of the four-point function and briefly comment on its properties, such as monodromy invariance, crossing symmetry, factorization, and limits. Published by the American Physical Society 2024

A Quantization for the Toy Model of Black Hole and a Suggestion to the Unification Theory

In my previous paper about the correlations between quantum mechanics and the four different natural forces, I suggested that there may be a fifth force or even the existence of a new particle. However, it remains a mystery to physicists, even after nearly a hundred years, that they cannot unify these four natural forces. This may be because there are indeed too many variables for them to consider. Also, there is a possibility that quantum mechanics may coexist with quantum field theory. In the present paper, this author proposes that there may be a misconception in the computational equation for relative time or gaps in the system for measuring time between quantum mechanics and general relativity. Hence, one may still not be able to unify these natural forces. This author suggests that we may need to rewrite parts of quantum mechanics – the Schrödinger equation – or even the general relativity equation. Additionally, this author proposes that there may be a bridge equation converting between quantum mechanics and general relativity. Moreover, this author has employed the non-trivial zeta zeros to simulate the black hole or the so-called black hole toy model. In practice, there may be an electromagnetic field surrounding the boundary of the black hole, as well as the existence of a continuum along the boundary contour. This author hopes that, in such a case, we may decode those high-frequency electromagnetic waves into useful information and take a further step toward verifying Stephen Hawking’s famous theory on black hole radiation and information entropy. In fact, this author has used the HKLam statistical model theory to express the electromagnetic field energy-stress tensor (with the possibility of quantization) to analogically establish a quantized model for the Einstein Gravitational Field Equation. Hence, the problem of quantum gravity may then be solved. Last but not least, this author also expects that humanity may finally find a way to unify quantum mechanics and general relativity through modifications to the current quantum gravity theory, such as my proposed bridge-converting equation, etc.

Semiclassical solution of black hole information paradox

Abstract We resolve black hole information paradox within semiclassical gravity, in a manner that does not depend on details of unknown quantum gravity. Our crucial insight is that outgoing Hawking particles are physical only far from the black hole horizon, so they are created far from the horizon and entangled with degrees of freedom closer to the horizon. The latter degrees of freedom can be understood as quasi-classical coherent states, implying that Hawking radiation is accompanied with additional radiation similar to classical radiation by which the black hole loses hair during the classical gravitational collapse. The two kinds of radiation are entangled, which resolves black hole information paradox.

The Black Hole Information Paradox: Is Omniscience a Fundamental Property of the Universe?

We seek to examine the ontological aspects of the resolution of the black hole information paradox. Several concepts which are now central to our understanding of quantum mechanics arose from our resolution to this paradox, and these concepts point to the conservation of all information, even on a quantum level. If quantum information is conserved and can never be erased or destroyed, then this indicates that all information is at least theoretically, ultimately retrievable and knowable from the event horizon of the universe. Ontologically, this supports the contention that a repository of all information in the universe must therefore exist. Herein, we trace the steps in this contention and conclude with the argument that our understanding of the universe points to the existence of an omniscient entity.

Unraveling the Black Hole Information Paradox: An Interdisciplinary Approach with the McGinty Equation

In the captivating realm of theoretical physics, the Black Hole Information Paradox stands as a formidable challenge, challenging the boundaries of our understanding of quantum mechanics and general relativity. This paradox, which questions the fate of information entering a black hole, contradicts the foundational principles of quantum theory, which assert that information should be conserved. Current models and theories, while providing substantial insights, fall short in resolving this paradox, mainly due to the complex interplay between quantum mechanics and the intense gravitational fields of black holes. This paper introduces the McGinty Equation (MEQ) as an innovative tool to bridge these gaps and unravel the complexities surrounding black holes and information conservation.

Multipartite Correlations in Parikh-Wilczek Non-Thermal Spectrum.

In this study, we systematically investigate the multipartite correlations in the process of black hole radiation via the Parikh-Wilczek tunneling model. We examine not only the correlations among Hawking radiations but also the correlations between the emissions and the remainder of the black hole. Our findings indicate that the total correlation among emitted particles continues to increase as the black hole evaporates. Additionally, we observe that the bipartite correlation between the emissions and the remainder of the black hole initially increases and then decreases, while the total correlation of the entire system monotonically increases. Finally, we extend our analysis to include quantum correction and observe similar phenomena. Through this research, we aim to elucidate the mechanism of information conservation in the black hole information paradox.

Page curves in holographic superconductors

Considering a doubly holographic model, we study the black hole information paradox for the eternal AdSd-RN black hole coupled to and in equilibrium with a d-dimensional conformal bath whose state has been deformed by the charged scalar field coupled to a U(1) gauge field. Without a brane, the spontaneous symmetry breaking of the gauge field on boundary systems can induce a second-order phase transition of the charged scalar field at the critical temperature, known as holographic superconductors. The bath deformation can significantly change its entanglement dynamics with the black hole, resulting in variations in the Page curve and Page time. Our results indicate that characteristic parameters of the Page curve, such as entanglement velocity, initial area difference and Page time, can be used as suitable probes to detect superconducting phase transitions. In particular, the entanglement velocity can also probe both Kasner flows and Josephson oscillations. When keeping the endpoint of the radiation region fixed at twice the critical Page point, the entanglement velocity (the internal backreaction) has a more significant influence on the Page time compared to the initial area difference (the external backreaction). Published by the American Physical Society 2024

Non-trivial saddles in microscopic description of black holes

Non-trivial gravitational saddles have played a key role in the island proposal for the black hole information paradox. It is worth asking if non-trivial saddles exist in microscopic descriptions of black holes. We show this to be the case for 1/8 BPS black holes in N\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{N} $$\\end{document} = 8 String Theory in a duality frame, where all charges are Ramond Ramond. The saddles are in the Coulomb branch, where they describe marginally stable bound states of the constituent branes, and correspond to vacua of the BFSS model. The non-perturbative suppression scale is determined by the binding energy. We comment on possible relevance of our results for developing string theoretic parallels of astrophysical black holes.

Superoscillations in high energy physics and gravity

We explore superoscillations within the context of classical and quantum field theories, presenting novel solutions to Klein–Gordon’s, Dirac’s, Maxwell’s and Einstein’s equations. In particular, we illustrate a procedure of second quantization of fields and how to construct a Fock space which encompasses Superoscillating states. Furthermore, we extend the application of superoscillations to quantum tunnelings, scatterings and mixings of particles, squeezed states and potential advancements in laser interferometry, which could open new avenues for experimental tests of quantum gravity effects. By delving into the relationship among superoscillations and phenomena such as Hawking radiation, the black hole (BH) information and the Firewall paradox, we propose an alternative mechanism for information transfer across the BH event horizon.

Entanglement islands read perfect-tensor entanglement

In this paper, we make use of holographic Boundary Conformal Field Theory (BCFT) to simulate the black hole information problem in the semi-classical picture. We investigate the correlation between a portion of Hawking radiation and entanglement islands by the area of an entanglement wedge cross-section. Building on the understanding of the relationship between entanglement wedge cross-sections and perfect tensor entanglement as discussed in reference [18], we make an intriguing observation: in the semi-classical picture, the positioning of an entanglement island automatically yields a pattern of perfect tensor entanglement. Furthermore, the contribution of this perfect tensor entanglement, combined with the bipartite entanglement contribution, precisely determines the area of the entanglement wedge cross-section.

Reconstructing the Gravitational Hologram with Quantum Information

Maldacena’s 1997 discovery of gauge/gravity duality promised to provide a complete understanding of quantum effects in gravity, by relating gravitating quantum systems to conventional quantum field theories on fixed backgrounds. Although much has been learned, this initial promise has not been completely fulfilled, due to lingering questions associated with the basic dictionary describing the way observables are mapped between one description and the other. While the dictionary is under good control for observables near the boundary, and also at the level of perturbation theory about a classical bulk spacetime for observables further in, non-perturbative questions critical for a full resolution of the black hole information problem remain to be fully answered. Over the last few years, however, a number of developments arising from the application of quantum information theory to AdS/CFT seem to be indicating that it may now be possible to address some of these questions. This GGI workshop brought together experts and young researchers, in order to capitalize on these developments.

Holographic image features of Hayward-AdS black hole surrounded by quintessence dark energy

By employing the AdS/CFT correspondence, we investigate the holographic images of Hayward-AdS black hole enveloped by quintessence dark energy. The AdS boundary is equipped with a Gaussian oscillation source, which give rise to the response generated on the opposing side of the boundary after it propagated in the bulk. With the aid of a special wave optics system, the holographic images of black hole in the bulk can be constructed. When the observation position is located at the north pole of boundary, the virtual screen displays a sequence of closed concentric ring structures. There is invariably one of these rings consistently marked by an exceptionally high level of observational intensity, namely the holographic Einstein ring, which corresponds to the position of photon ring in the geometric optics. For other observation positions, the ring transforms gradually into a luminous arc-like shape and ultimately into a light spot positioned on the screen. And, the effects of the relevant state parameters on the characteristics of black hole holographic image, including the observed intensity, width or size of the ring, and proportion range, are in-depth examined. It is believed that the critical information of the Hayward-AdS black hole surrounded by quintessence can be obtained from these holographic images, which will help us understand the geometric characteristics of regular spacetime more deeply.

Entanglement island versus massless gravity

Entanglement islands play an essential role in the recent breakthrough in addressing the black hole information paradox. Inspired by double holography, it is conjectured that the entanglement islands can exist only in massive gravity. There are many pieces of evidence but also debates for this conjecture. This paper recovers the massless entanglement island in wedge holography with negative DGP gravity on the brane. However, the spectrum of negative DGP gravity includes a massive ghost, implying the model is unstable. Our work supports the view that there is no entanglement island in a well-defined braneworld model of massless gravity if one divides the radiation and black hole regions by minimizing entanglement entropy. However, such a partition results in a zero radiation region containing no information. Whether there are other physical non-trivial partitions of the radiation region is an open question and deserves further study.

A classical firewall transformation as a canonical transformation

The firewall transformation put forward by ’t Hooft in recent years has made ambitious claims of solving the firewall problem and the black hole information paradox while maintaining unitary evolution. However, the theory has received limited attention from the community, especially in regards to its foundations in purely classical gravitational physics. This paper investigates the underlying assumptions of ’t Hooft’s firewall transformation before quantization. We find that the limiting procedure used by ’t Hooft in order to obtain an identification of the quantum operators for ingoing and outgoing particles near a black hole is not consistent. We propose a correction, which involves a more relaxed approximation regime. In the new approximation regime, we find a new classical analog for the firewall transformation for spherical shells, which allows evolving the spherical shells’ dynamics past their point of collision. In the classical theory, no firewall is removed, as both ingoing and outgoing matter is present on every spacelike hypersurface, and it does not appear that any firewalls will be removed after a canonical quantization.

Deterministic Heat Death of Universe and Blackhole Information Paradox with Wormhole Negative Temperatures

Deterministic Heat Death of Universe and Blackhole Information Paradox with Wormhole Negative Temperatures

An exact, coordinate independent classical firewall transformation

A proposal for resolving the black hole information paradox was recently put forward by ’t Hooft in the form of his firewall transformation. Although this proposal has begun to gain some limited traction, its physical foundation is still somewhat obscure. Here we develop a classical Hamiltonian analog, which is oriented towards quantization, by using the canonical formalism developed by Arnowitt, Deser, and Misner (ADM). We use a model of two null, spherical shells in a Schwarzschild black hole background, and within our ADM formalism we are able to characterize the dynamics of the entire system, especially at the point of collision, and we reproduce the related Dray–’t Hooft–Redmount formula. Finally, we are able to find a classical analog for ’t Hooft’s firewall transformation. Unlike ’t Hooft’s firewall transformation and previous classical analogs, the classical firewall transformation we obtain is free from approximation and maintains the coordinate independence of the ADM formalism. We leave to future work the quantization of the theory.

Thermodynamics of a quantum corrected Reissner-Nordström black hole

In the modified Reissner-Nordström (RN) black hole with quantum excitations of spacetime, we investigate the quantum corrected thermodynamics. First, we calculate the thermodynamic quantities and examine the quantum corrections on the temperature, entropy and heat capacity. To ensure the black hole mass having the basic physics meaning, we obtain the critical state with Planck scale. Letting the thermal capacity equal zero, we derived the radiation remnant which is consistent with the critical state. Also, we analyze the thermal capacity and discuss the thermal stability of the black hole. Next, using the quantum tunneling method and taking into account the second-order WKB approximation, we calculate the tunneling probability of massless particle. It is found that the tunneling rate is regularized by the quantum excitations of spacetime. As well as, for the tunneling radiation, there are correlations between the emitted modes and holds the potential to address the black hole information loss problem. Besides, based on the unitary of the quantum tunneling, we obtained the corrected black hole entropy, which contains the logarithm and inverse of the black hole area.

The Page curve from the entanglement membrane

We study entanglement dynamics in toy models of black hole information built out of chaotic many-body quantum systems, by utilising a coarse-grained description of entanglement dynamics in such systems known as the ‘entanglement membrane’. We show that in these models the Page curve associated to the entropy of Hawking radiation arises from a transition in the entanglement membrane around the Page time, in an analogous manner to the change in quantum extremal surfaces that leads to the Page curve in semi-classical gravity. We also use the entanglement membrane prescription to study the Hayden-Preskill protocol, and demonstrate how information initially encoded in the black hole is rapidly transferred to the radiation around the Page time. Our results relate recent developments in black hole information to generic features of entanglement dynamics in chaotic many-body quantum systems.

Discreteness Unravels the Black Hole Information Puzzle: Insights from a Quantum Gravity Toy Model.

The black hole information puzzle can be resolved if two conditions are met. The first is that the information about what falls inside a black hole remains encoded in degrees of freedom that persist after the black hole completely evaporates. These degrees of freedom should be capable of purifying the information. The second is if these purifying degrees of freedom do not significantly contribute to the system's energy, as the macroscopic mass of the initial black hole has been radiated away as Hawking radiation to infinity. The presence of microscopic degrees of freedom at the Planck scale provides a natural mechanism for achieving these two conditions without running into the problem of the large pair-creation probabilities of standard remnant scenarios. In the context of Hawking radiation, the first condition implies that correlations between the in and out Hawking partner particles need to be transferred to correlations between the microscopic degrees of freedom and the out partners in the radiation. This transfer occurs dynamically when the in partners reach the singularity inside the black hole, entering the UV regime of quantum gravity where the interaction with the microscopic degrees of freedom becomes strong. The second condition suggests that the conventional notion of the vacuum's uniqueness in quantum field theory should fail when considering the full quantum gravity degrees of freedom. In this paper, we demonstrate both key aspects of this mechanism using a solvable toy model of a quantum black hole inspired by loop quantum gravity.

The Magical “Born Rule” and Quantum “Measurement”: Implications for Physics

I. The arena of quantum mechanics and quantum field theory is the abstract, unobserved and unobservable, M-dimensional formal Hilbert space ≠ spacetime. II. The arena of observations—and, more generally, of all events (i.e., everything) in the real physical world—is the classical four-dimensional physical spacetime. III. The “Born rule” is the random process “magically” transforming I into II. Wavefunctions are superposed and entangled only in the abstract space I, never in spacetime II. Attempted formulations of quantum theory directly in real physical spacetime actually constitute examples of “locally real” theories, as defined by Clauser and Horne, and are therefore already empirically refuted by the numerous tests of Bell’s theorem in real, controlled experiments in laboratories here on Earth. Observed quantum entities (i.e., events) are never superposed or entangled as they: (1) exclusively “live” (manifest) in real physical spacetime and (2) are not described by entangled wavefunctions after “measurement” effectuated by III. When separated and treated correctly in this way, a number of fundamental problems and “paradoxes” of quantum theory vs. relativity (i.e., spacetime) simply vanish, such as the black hole information paradox, the infinite zero-point energy of quantum field theory and the quantization of general relativity.