No Arabic abstract
Information about the collapsed matter in a black hole will be lost if Hawking radiations are truly thermal. Recent studies discover that information can be transmitted from a black hole by Hawking radiations, due to their spectrum deviating from exact thermality when back reaction is considered. In this paper, we focus on the spectroscopic features of Hawking radiation from a Schwarzschild black hole, contrasting the differences between the nonthermal and thermal spectra. Of great interest, we find that the energy covariances of Hawking radiations for the thermal spectrum are exactly zero, while the energy covariances are non-trivial for the nonthermal spectrum. Consequently, the nonthermal spectrum can be distinguished from the thermal one by counting the energy covariances of successive emissions, which provides an avenue towards experimentally testing the long-standing information loss paradox.
Various techniques to tackle the black hole information paradox have been proposed. A new way out to tackle the paradox is via the use of a pseudo-density operator. This approach has successfully dealt with the problem with a two qubit entangle system for a single black hole. In this paper, we present the interaction with a binary black hole system by using an arrangement of the three qubit system of Greenberger Horne Zeilinger (GHZ) state. We show that our results are in excellent agreement with the theoretical value. We have also studied the interaction between the two black holes by considering the correlation between the qubits in the binary black hole system. The results depict a complete agreement with the proposed model. In addition to the verification, we also propose how modern detection of gravitational waves can be used on our optical setup as an input source, thus bridging the gap with the gravitational waves observational resources in terms of studying black hole properties with respect to quantum information and entanglement.
An approach to black hole quantization is proposed wherein it is assumed that quantum coherence is preserved. A consequence of this is that the Penrose diagram describing gravitational collapse will show the same topological structure as flat Minkowski space. After giving our motivations for such a quantization procedure we formulate the background field approximation, in which particles are divided into hard particles and soft particles. The background space-time metric depends both on the in-states and on the out-states. We present some model calculations and extensive discussions. In particular, we show, in the context of a toy model, that the $S$-matrix describing soft particles in the hard particle background of a collapsing star is unitary, nevertheless, the spectrum of particles is shown to be approximately thermal. We also conclude that there is an important topological constraint on functional integrals.
In this work we show that single horizon black hole behaves as a laser. It is in many aspects conceptually analogous to Corley and Jacobson work on the two horizon black hole laser. We started by proposition that circumference of the black hole horizon holds the natural (integer) quantum number of corresponding reduced Comptons wave length of some boson systems in great canonical ensemble. For macroscopic black hole ground state is practically totally occupied while other states are practically totally unoccupied which is a typical Bose condensation. Number of the systems in this condensate represents black hole entropy. For microscopic black hole few lowest energy levels are occupied with almost equivalent population (with negative chemical potential) while all other energy states (with positive chemical potential) are practically unoccupied. It implies that here not only spontaneous but also stimulated emission of radiation comparable with spontaneous emission occurs. By Hawking evaporation any macroscopic black hole turns out in a microscopic black hole that yields, in a significant degree, coherent stimulated emission of the radiation. It implies that by total black hole evaporation there is no decoherence, i.e. information loss. Finally, a mass duality characteristic for suggested black hole model corresponding to string T-duality is discussed.
Pseudo-density matrices are a generalisation of quantum states and do not obey monogamy of quantum correlations. Could this be the solution to the paradox of information loss during the evaporation of a black hole? In this paper we discuss this possibility, providing a theoretical proposal to extend quantum theory with these pseudo-states to describe the statistics arising in black-hole evaporation. We also provide an experimental demonstration of this theoretical proposal, using a simulation in optical regime, that tomographically reproduces the correlations of the pseudo-density matrix describing this physical phenomenon.
It has been shown that the nonthermal spectrum of Hawking radiation will lead to information-carrying correlations between emitted particles in the radiation. The mutual information carried by such correlations can not be locally observed and hence is dark. With dark information, the black hole information is conserved. In this paper, we look for the spherically symmetric black hole solution in the background of dark matter in mimetic gravity and investigate the radiation spectrum and dark information of the black hole. The black hole has a similar spacetime structure to the Schwarzschild case, while its horizon radius is decreased by the dark matter. By using the statistical mechanical method, the nonthermal radiation spectrum is calculated. This radiation spectrum is very different from the Schwarzschild case at its last stage because of the effect of the dark matter. The mimetic dark matter reduces the lifetime of the black hole but increases the dark information of the Hawking radiation.