Information Paradox Research Articles

On the use of smart contracts to cope with Arrow’s Information Paradox on trade secrets exchange: method and prototype

The state of the art contains systems for the transfer of intangible assets protected by intellectual property rights, consolidated by legal monopolies, be them attributive systems (such as patents and industrial designs) or reliant on automatic protection (such as copyright and neighboring rights). Some of these systems, or their respective methods, are described in the scientific literature. Of this set, some methods employ blockchain technology and a smaller subset also employs smart contracts technology, despite both technologies being mutually independent. Although trade secrets also constitute monopolies, computerized solutions or cryptographic environments used for other types of goods protected by other forms of intellectual property cannot be transferred to these assets, due to their sui generis nature, lacking of monopoly regardless of its non-disclosure. The need for maintenance of secrecy is due to Arrow Information Paradox, the phenomenon by which the disclosure of the secret constitutes by itself its transference. This phenomenon impairs the potential for transference of industrial secrets and prevents the adoption of the existing systems applicable to other types of intangible assets. Through this work a method for transferring industrial secrets is presented, using smart contracts embedded on a blockchain, for solving two of the three component elements of the Paradox, namely capability and reliability, and presupposes the third, relevance. The method is also validated through the development of a prototype, based on Ethereum blockchain.

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.

Topology-induced quantum transition in multiparticle systems in vicinity of a black hole

The qualitative change of the type of particle trajectory homotopy in close vicinity of general-relativistic gravitational singularity affects quantum statistics in systems of identical indistinguishable particles at passing the photon sphere rim of a Schwarzschild black hole. This causes a local departure from the Pauli exclusion principle, which results in some high energy effects manifesting themselves when the matter is falling into a black hole. The release of the energy can take place at the rim of the photon sphere of a black hole due to the decay of Fermi spheres in highly compressed fermion systems entering this region. The effect is observable at activity of quasars or at collapses of neutron star mergers. The related supplementation to conventional models of the accretion disc luminosity by additional radiation from close vicinity of the event horizon of a massive black hole powering super-luminous quasar is proposed and compared with observations. The source of short-lasting gamma-ray bursts has been also identified at collapses of unstable neutron star mergers due to the decay of Fermi sphere of neutrons. The duration and spectrum of the related e-m radiation bursts estimated by the Fermi golden rule for the Fermi sphere decay agree with observations. The quantum statistics effect contributes also to the radiation of transients of micro-quasars and short lasting brightening episodes in closer active galactic nuclei. The proposed quantum effect changes the premises for the current discussion of the information paradox and hypothesis of the black hole firewall.

Soft graviton exchange and the information paradox

We show that there is a remarkable phase in quantum gravity where gravitational scattering amplitudes mediated by virtual gravitons can be calculated explicitly in effective field theory, when the impact parameter b satisfies LPl≪b≲RS, with RS being the Schwarzschild radius. This phase captures collisions with energies satisfying s≫γMPl (with γ∼MPl/MBH) near the horizon. We call this the black hole eikonal phase, in contrast to its flat space analog where collisions are trans-Planckian. Hawking’s geometric optics approximation neglects gravitational interactions near the horizon, and results in thermal occupation numbers in the Bogoliubov coefficients. We show that these interactions are mediated by graviton exchange in 2→2 scattering near the horizon, and explicitly calculate the S-matrix nonperturbatively in MPl/MBH. This involves a resummation of infinitely many ladder diagrams near the horizon, all mediated by virtual soft gravitons. The S-matrix turns out to be a pure phase upon this resummation and is agnostic of Planckian physics and any specific ultraviolet completion. In contrast to the flat-space eikonal limit, the black hole eikonal phase captures collisions of extremely low energy near the horizon. Published by the American Physical Society 2024

A qualitative study on patients’ and health care professionals’ perspectives regarding care delivered during CIED operation

BackgroundCardiac implantable electronic devices (CIEDs) has proven to be an invaluable tool in the practice of cardiology. Patients who have undergone CIED surgery with local anesthesia may result in fear, insecurity and suffering. Some studies have put efforts on ways to improve intraoperative experience of patients with local anesthesia, but researches concerning experiences of CIED patients during surgery is in its infancy.MethodsBased on semi-structured and in-depth interviews, a qualitative design was conducted in a tertiary general hospital in China from May 2022 to July 2023.Purposeful sampling of 17 patients received CIED surgery and 20 medical staff were interviewed. Thematic analysis with an inductive approach was used to identify dominant themes.ResultsFour themes emerged from the data: (1) Safety and success is priority; (2) Humanistic Caring is a must yet be lacking; (3) Paradox of surgery information given; (4) Ways to improve surgery experiences in the operation.ConclusionsIntraoperative care is significant for CIED surgery. To improve care experience during surgery, healthcare professionals should pay attention to patients’ safety and the factors that affecting humanistic caring in clinical practice. In addition, information support should consider information-seeking styles and personal needs. Besides, the four approaches presented in this study are effective to improve the intraoperative care experience.

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

Information Paradoxes of the First American War (1775–1783)

Information Paradoxes of the First American War (1775–1783)

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.

Theory dependence of black hole interior reconstruction and the extended strong subadditivity

An AdS eternal black hole in equilibrium with a finite temperature bath presents a Hawking-like information paradox due to a continuous exchange of radiation with the bath. The non-perturbative gravitational effect, the replica wormhole, cures this paradox by introducing a non-trivial entanglement wedge for the bath after Page time. In this paper, we analyse the theory dependence of this non-perturbative effect by randomising the boundary conditions of some of the bulk matter fields. We explicitly analyse this in JT gravity by introducing a matter CFT in the AdS region with random boundary conditions at the AdS boundary that are drawn from a distribution. Using the island formula and the extended strong subadditivity due to Carlen and Lieb, we show that at late times the black hole interior is contained inside the entanglement wedge of a reference Hilbert space that encodes the information about the random boundary conditions. Consequently, the reconstruction of the black hole interior from the radiation, in particular the region near the singularity, requires a detailed knowledge of the theory.

A nonperturbative approach to Hawking radiation and black hole quantum hair

We present a nonperturbative derivation of the subleading order in Hawking radiation based on diffeomorphism symmetry breaking during black hole evaporation. The diffeomorphism group of horizon admits a nontrivial phase factor which encodes information about infalling matter during formation. This nonintegrable phase represents the black hole quantum hair as it arises from the diffeomorphisms that change the physical state of the black hole. During evaporation, the decrease in total area breaks the diffeomorphism symmetry and leads to a dynamical shift in that phase factor. This shift affects the usual Hawking spectrum via dispersion relation and results in the subleading term in Hawking radiation. The higher order terms are locally insensitive to the Unruh radiation due to the lack of diffeomorphism groups on the local Rindler horizon at the low energy scale. This explains the generic difference between Hawking radiation and Unruh radiation. In addition, this phase shift indicates the decrease of the total number of degrees of freedom in horizon phase space during evaporation as past Page time. This enables us to escape from the firewall paradox and provide an account for the resolution to the information paradox.

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.

Nonperturbative gravity corrections to bulk reconstruction

We introduce a new algebraic framework for understanding nonperturbative gravitational aspects of bulk reconstruction with a finite or infinite-dimensional boundary Hilbert space. We use relative entropy equivalence between bulk and boundary with an inclusion of nonperturbative gravitational errors, which give rise to approximate recovery. We utilize the privacy/correctability correspondence to prove that the reconstruction wedge, the intersection of all entanglement wedges in pure and mixed states, manifestly satisfies bulk reconstruction. We explicitly demonstrate that local operators in the reconstruction wedge of a given boundary region can be recovered in a state-independent way for arbitrarily large code subspaces, up to nonperturbative errors in GN . We further discuss state-dependent recovery beyond the reconstruction wedge and the use of the twirled Petz map as a universal recovery channel. We discuss our setup in the context of quantum islands and the information paradox.

Magnetic string matter collapse in rainbow gravity

This work investigates the dynamics of a collapsing magnetic string dust and string fluid in the Plank Era via spherically symmetric rainbow geometry. The field equations are modified and solved to obtain the dynamical quantities, including mass density, pressure, string tension, and magnetic field strength. These quantities are presented graphically. The energy conditions are computed showing that all the dynamical quantities are associated with physical matter. The distance and moment of apparent horizon formation are computed. The magnetic field is found to affect the distance and moment of the apparent horizon’s formation. It accelerates the collapsing process. Further, the dynamical variables are maximum in the collapsing configuration’s center leading to compact object (black hole) formation. The probing particle’s energy affects all the dynamical variables of the fluid in a direct proportion. This resolves the information paradox as a particle with greater energy grasps the information from a particle with lesser energy and takes it out in the real world.

Grothendieck’s point of view and complexity in the black hole paradox

These are some speculations on how Grothendieck’s point of view and the idea of complexity dynamics can come together in the problem of explaining the black hole information paradox. They are neither complete, nor final, but can seem like a new direction of research. If read as such they could prove useful to some researchers. The basic idea is that entanglement alone cannot fully account for the information extraction in black hole contexts. Complexity has been proposed as an alternative but remains a vague concept. I employ Grothendieck’s point of view to expand the idea of entanglement entropy to a categorical context in which the objects (states) and their maps are considered together and the map space has additional topological and geometric structure that intermingles with the object set of the category via Sieves, Sheafs, and Toposes.

The Paradox of Information and Communication Technology Demands at Work on Creativity

The Paradox of Information and Communication Technology Demands at Work on Creativity

Stable charged gravastar model in cylindrically symmetric space-time

In this paper, we have extended the idea of gravitational Bose–Einstein condensate star (gravastar) to charged gravastar system and explored the role of charge in gravastar formation and its properties. We have used the most general line element in cylindrically symmetric space-time. In this approach, the existence of singularity at the center of gravastar is removed and the event horizon is replaced by the thin shell approximation. The proper length of the shell is calculated along with the energy of the thin shell in presence of charge. The entropy calculation shows that the entropy of the configuration is smaller than that of a quasi-black hole system and even smaller than that of a classical black hole. Unlike black hole, the gravastar system is a stable configuration and in our approach, there is no information paradox.

Glimmers of a post-geometric perspective

Quantum gravitational effects can become important at low energy if the wavefunction of the metric field fails to be peaked around a classical configuration. We try to understand such deviations from classicality within canonical quantum gravity by introducing a ‘fluid of observers’ in the low energy theory and defining a distance operator ‘at equal time’ among them. We find that, even in the presence of relevant fluctuations in the metric field, a ‘locally flat’ limit is recovered in the neighbourhood of each observer. Deviations from classicality have no particular consequence, locally. However, at larger separations the expectation value of the distance operator behaves differently than a standard Riemannian distance. In particular, it is non-additive and thus cannot be obtained by the integral of a differential line element. This emerging ‘beyond Riemannian’ geometry is a metric space similar to embedded Riemannian manifolds equipped with chord distances that ‘cut through’ the ambient space. We study deviations from flat space by looking at triangles in the limit where their sizes go to zero. Beyond-Riemannian deviations with respect to flat space are of the same order as standard Riemannian ones, but qualitatively different. Possible connections with holography and with the black hole information paradox are briefly discussed.

The holar wind

String theory in AdS3 with purely NS-NS fluxes and vanishing RR moduli has a continuum of winding string excitations in radial plane wave states. BTZ black holes can emit such strings, which then flow out toward the AdS3 boundary as a stream of massive quanta, and form a black hole analogue of the solar wind. The winding string sector thus provides a decay channel for the black hole to evaporate without having either to couple the system to an external reservoir or to match the AdS3 throat onto an asymptotically flat region. We compute the emission amplitude of this “holar wind” in the semi-classical approximation, and consider the associated version of the black hole information paradox.

Islands in Generalized Dilaton Theories

This work systematically studies the island formula in the general asymptotically flat eternal black holes in generalized dilaton gravity theories or higher-dimensional spherical black holes. Under some reasonable and mild assumptions, we prove that (the boundary of) the island always appears barely outside the horizon in the late time of Hawking radiation, so the information paradox is resolved. In particular, we find a proper island in the Liouville black hole that solves the previous the puzzle.