The Big Bang, quantum gravity and black-hole information loss

2012 ◽  
pp. 410-418
Author(s):  
Roger Penrose
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Big Bang ◽  
Information Loss ◽  
Black Hole Information ◽  
The Big Bang

scholarly journals Hidden messenger from quantum geometry: Towards information conservation in quantum gravity

2018 ◽  
Vol 33 (18) ◽  
pp. 1850103 ◽  
Author(s):  
Xiao-Kan Guo ◽  
Qing-Yu Cai
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Loop Quantum Gravity ◽  
Information Loss ◽  
Quantum Geometry ◽  
Spin Network ◽  
General Derivation ◽  
Black Hole Information ◽  
Network States ◽  
Quantum Geometries

The back reactions of Hawking radiation allow nontrivial correlations between consecutive Hawking quanta, which gives a possible way of resolving the paradox of black hole information loss known as the hidden messenger method. In a recent work of Ma et al. [ arXiv:1711.10704 ], this method is enhanced by a general derivation using small deviations of the states of Hawking quanta off canonical typicality. In this paper, we use this typicality argument to study the effects of generic back reactions on the quantum geometries described by spin network states, and discuss the viability of entropy conservation in loop quantum gravity. We find that such back reactions lead to small area deformations of quantum geometries including those of quantum black holes. This shows that the hidden-messenger method is still viable in loop quantum gravity, which is a first step towards resolving the paradox of black hole information loss in quantum gravity.

scholarly journals Through a black hole into a New Universe

2021 ◽  
Author(s):  
Robert Brandenberger ◽  
Lavinia Heisenberg ◽  
Jakob Robnik
Keyword(s):  
Black Hole ◽  
Big Bang ◽  
Information Loss ◽  
Black Hole Horizon ◽  
Continuous Transition ◽  
Weyl Curvature ◽  
Simultaneous Resolution ◽  
Black Hole Information ◽  
Information Loss Problem

We show that an S-brane which arises in the inside of the black hole horizon when the Weyl curvature reaches the string scale induces a continuous transition between the inside of the black hole and the beginning of a new universe. This provides a simultaneous resolution of both the black hole and Big Bang singularities. In this context, the black hole information loss problem is also naturally resolved.

SHOCK WAVE COSMOLOGY INSIDE A BLACK HOLE: THE CASE OF NON-CRITICAL EXPANSION

2004 ◽  
Vol 01 (03) ◽  
pp. 429-443
Author(s):  
JOEL SMOLLER ◽  
BLAKE TEMPLE
Keyword(s):  
Shock Wave ◽  
Black Hole ◽  
Equation Of State ◽  
Closed System ◽  
Big Bang ◽  
Speed Of Light ◽  
State Formula ◽  
The Big Bang

We derive and analyze the equations that extend the results in [20,21] to the case of non-critical expansion k≠0. By an asymptotic argument we show that the equation of state [Formula: see text] plays the same distinguished role in the analysis when k≠0 as it does when k=0: only for this equation of state does the shock emerge from the Big Bang at a finite nonzero speed — the speed of light. We also obtain a simple closed system that extends the case [Formula: see text] considered in [20,21] to the case of a general positive, increasing, convex equation of state p=p(ρ).

scholarly journals Global symmetry, Euclidean gravity, and the black hole information problem

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Daniel Harlow ◽  
Edgar Shaghoulian
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Global Symmetries ◽  
Close Connection ◽  
Usual Sense ◽  
Global Symmetry ◽  
Recent Argument ◽  
Black Hole Information ◽  
Information Problem ◽  
Low Dimensional

Abstract In this paper we argue for a close connection between the non-existence of global symmetries in quantum gravity and a unitary resolution of the black hole information problem. In particular we show how the essential ingredients of recent calculations of the Page curve of an evaporating black hole can be used to generalize a recent argument against global symmetries beyond the AdS/CFT correspondence to more realistic theories of quantum gravity. We also give several low-dimensional examples of quantum gravity theories which do not have a unitary resolution of the black hole information problem in the usual sense, and which therefore can and do have global symmetries. Motivated by this discussion, we conjecture that in a certain sense Euclidean quantum gravity is equivalent to holography.

scholarly journals Quantum Gravity Phenomenology from the Thermodynamics of Spacetime

Universe ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 50
Author(s):  
Ana Alonso-Serrano ◽  
Marek Liška
Keyword(s):  
Quantum Gravity ◽  
Big Bang ◽  
Einstein Equations ◽  
Logarithmic Term ◽  
Quantum Gravity Phenomenology ◽  
Gravity Effects ◽  
Energy Quantum ◽  
The Big Bang ◽  
Big Bang Singularity ◽  
Modified Dynamics

This work is based on the formalism developed in the study of the thermodynamics of spacetime used to derive Einstein equations from the proportionality of entropy within an area. When low-energy quantum gravity effects are considered, an extra logarithmic term in the area is added to the entropy expression. Here, we present the derivation of the quantum modified gravitational dynamics from this modified entropy expression and discuss its main features. Furthermore, we outline the application of the modified dynamics to cosmology, suggesting the replacement of the Big Bang singularity with a regular bounce.

scholarly journals A PROPOSAL TO RESOLVE THE BLACK HOLE INFORMATION PARADOX

2002 ◽  
Vol 11 (10) ◽  
pp. 1537-1540 ◽  
Author(s):  
SAMIR D. MATHUR
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Quantum Gravity ◽  
Bound State ◽  
Nonlocal Effects ◽  
Information Paradox ◽  
Microscopic Scale ◽  
Gravity Effects ◽  
Black Hole Information

The entropy and information puzzles arising from black holes cannot be resolved if quantum gravity effects remain confined to a microscopic scale. We use concrete computations in nonperturbative string theory to argue for three kinds of nonlocal effects that operate over macroscopic distances. These effects arise when we make a bound state of a large number of branes, and occur at the correct scale to resolve the paradoxes associated with black holes.

scholarly journals Wormhole calculus, replicas, and entropies

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Steven B. Giddings ◽  
Gustavo J. Turiaci
Keyword(s):  
Black Hole ◽  
Probability Distributions ◽  
Information Loss ◽  
Coupling Constants ◽  
Quantum Mechanical ◽  
Standard Description ◽  
Standard Quantum ◽  
Black Hole Information ◽  
Baby Universes ◽  
Baby Universe

Abstract We investigate contributions of spacetime wormholes, describing baby universe emission and absorption, to calculations of entropies and correlation functions, for example those based on the replica method. We find that the rules of the “wormhole calculus”, developed in the 1980s, together with standard quantum mechanical prescriptions for computing entropies and correlators, imply definite rules for limited patterns of connection between replica factors in simple calculations. These results stand in contrast with assumptions that all topologies connecting replicas should be summed over, and call into question the explanation for the latter. In a “free” approximation baby universes introduce probability distributions for coupling constants, and we review and extend arguments that successive experiments in a “parent” universe increasingly precisely fix such couplings, resulting in ultimately pure evolution. Once this has happened, the nontrivial question remains of how topology-changing effects can modify the standard description of black hole information loss.

scholarly journals Binary Black Hole Information Loss Paradox and Future Prospects

Entropy ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 1387
Author(s):  
Ayan Mitra ◽  
Pritam Chattopadhyay ◽  
Goutam Paul ◽  
Vasilios Zarikas
Keyword(s):  
Black Hole ◽  
Information Loss ◽  
Complete Agreement ◽  
Future Prospects ◽  
Information Loss Paradox ◽  
Binary Black Hole ◽  
Proposed Model ◽  
Qubit System ◽  
Input Source ◽  
Black Hole Information

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 wave’s observational resources in terms of studying black hole properties with respect to quantum information and entanglement.

scholarly journals Supermassive black holes in the early Universe

2015 ◽  
Vol 471 (2184) ◽  
pp. 20150449 ◽  
Author(s):  
F. Melia ◽  
T. M. McClintock
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Accretion Rate ◽  
Big Bang ◽  
Supermassive Black Holes ◽  
Active Mass ◽  
Time Compression ◽  
First And Second Generation ◽  
The Big Bang ◽  
Friedmann Robertson Walker

The recent discovery of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.3 has exacerbated the time compression problem implied by the appearance of supermassive black holes only approximately 900 Myr after the big bang, and only approximately 500 Myr beyond the formation of Pop II and III stars. Aside from heralding the onset of cosmic re-ionization, these first and second generation stars could have reasonably produced the approximately 5–20  M ⊙ seeds that eventually grew into z approximately 6–7 quasars. But this process would have taken approximately 900 Myr, a timeline that appears to be at odds with the predictions of Λ CDM without an anomalously high accretion rate, or some exotic creation of approximately 10 5   M ⊙ seeds. There is no evidence of either of these happening in the local Universe. In this paper, we show that a much simpler, more elegant solution to the supermassive black hole anomaly is instead to view this process using the age–redshift relation predicted by the R h = ct Universe, an Friedmann–Robertson–Walker (FRW) cosmology with zero active mass. In this context, cosmic re-ionization lasted from t approximately 883 Myr to approximately 2 Gyr ( 6 ≲ z ≲ 15 ), so approximately 5–20  M ⊙ black hole seeds formed shortly after re-ionization had begun, would have evolved into approximately 10 10   M ⊙ quasars by z approximately 6–7 simply via the standard Eddington-limited accretion rate. The consistency of these observations with the age–redshift relationship predicted by R h = ct supports the existence of dark energy; but not in the form of a cosmological constant.

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