Correlation, entropy, and information transfer in black hole radiation

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 quantu...

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...

There has been recent speculation that the tunneling paradigm for Hawking radiation could -- after quantum-gravitational effects have suitably been incorporated -- provide a means for resolving the (black hole) information loss paradox. A prospective quantum-gravitational effect is the logarithmic-order correction to the Bekenstein-Hawking entropy/area law. In this letter, it is demonstrated that, even with the inclusion of the logarithmic correction (or, indeed, the quantum ...

We investigate the features of the non-corrected thermal (non-thermal) spectrum and the quantum corrected thermal (non-thermal) spectrum. We find that: (i) using the quantum corrected non-thermal spectra, the black hole radiation as tunneling is an entropy conservation process, and thus black hole evaporation process is unitary; (ii) there are no obvious differences between all spectra except for near the Planck mass scale by comparing their average emission energies, average...

When two objects have gravitational interaction between them, they are no longer independent of each other. In fact, there exists gravitational correlation between these two objects. Inspired by E. Verlinde's paper, we first calculate the entropy change of a system when gravity does positive work on this system. Based on the concept of gravitational correlation entropy, we prove that the entropy of a Schwarzschild black hole originates from the gravitational correlations betw...

The Generalized Uncertainty Principle (GUP), motivated by current alternatives of quantum gravity, produces significant modifications to the Hawking radiation and the final stage of black hole evaporation. We show that incorporation of the GUP into the quantum tunneling process (based on the null-geodesic method) causes correlations between the tunneling probability of different modes in the black hole radiation spectrum. In this manner, the quantum information becomes encryp...

This article is divided into three parts. First, a systematic derivation of the Hawking radiation is given in three different ways. The information loss problem is then discussed in great detail. The last part contains a concise discussion of black hole thermodynamics. This article was published as chapter $6$ of the IOP book "Lectures on General Relativity, Cosmology and Quantum Black Holes" (July $2017$).

Hawking's 1974 calculation of thermal emission from a classical black hole led to his 1976 proposal that information may be lost from our universe as a pure quantum state collapses gravitationally into a black hole, which then evaporates completely into a mixed state of thermal radiation. Another possibility is that the information is not lost, but is stored in a remnant of the evaporating black hole. A third idea is that the information comes out in nonthermal correlations w...

Black holes emit thermal radiation (Hawking effect). If after black-hole evaporation nothing else were left, an arbitrary initial state would evolve into a thermal state (`information-loss problem'). Here it is argued that the whole evolution is unitary and that the thermal nature of Hawking radiation emerges solely through decoherence -- the irreversible interaction with further degrees of freedom. For this purpose a detailed comparison with an analogous case in cosmology (e...

The black hole information puzzle arises from a discrepancy between conclusions drawn from general relativity and quantum theory about the nature of the radiation emitted by a black hole. According to Hawking's original argument, the radiation is thermal and its entropy thus increases monotonically as the black hole evaporates. Conversely, due to the reversibility of time evolution according to quantum theory, the radiation entropy should start to decrease after a certain tim...