scholarly journals Observations of Hawking radiation: the Page curve and baby universes

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Donald Marolf ◽  
Henry Maxfield
Keyword(s):  
Black Holes ◽  
Quantum Systems ◽  
Late Time ◽  
Asymptotically Flat ◽  
Black Hole Information ◽  
Flat Spacetimes ◽  
The Cost ◽  
Baby Universes ◽  
Time Extrapolation ◽  
Asymptotic Observers

AbstractWe reformulate recent insights into black hole information in a manner emphasizing operationally-defined notions of entropy, Lorentz-signature descriptions, and asymptotically flat spacetimes. With the help of replica wormholes, we find that experiments of asymptotic observers are consistent with black holes as unitary quantum systems, with density of states given by the Bekenstein-Hawking formula. However, this comes at the cost of superselection sectors associated with the state of baby universes. Spacetimes studied by Polchinski and Strominger in 1994 provide a simple illustration of the associated concepts and techniques, and we argue them to be a natural late-time extrapolation of replica wormholes. The work aims to be self-contained and, in particular, to be accessible to readers who have not yet mastered earlier formulations of the ideas above.

scholarly journals Deriving Weak Deflection Angle by Black Holes or Wormholes using Gauss-Bonnet Theorem

2021 ◽  
Author(s):  
Yashmitha Kumaran ◽  
Ali Övgün
Keyword(s):  
Black Holes ◽  
Gravitational Lensing ◽  
Deflection Angle ◽  
Weak Field ◽  
Plasma Medium ◽  
Asymptotically Flat ◽  
Finite Distance ◽  
Flat Spacetimes ◽  
The Deflection Angle ◽  
Bonnet Theorem

In this review, various researches on finding the bending angle of light deflected by a massive gravitating object which regard the Gauss-Bonnet theorem as the premise have been revised. Primarily, the Gibbons and Werner method is studied apropos of the gravitational lensing phenomenon in the weak field limits. Some exclusive instances are deliberated while calculating the deflection angle, beginning with the finite-distance corrections on non-asymptotically flat spacetimes. Effects of plasma medium is then inspected to observe its contribution to the deflection angle. Finally, the Jacobi metric is explored as an alternative method, only to arrive at similar results. All of the cases are probed in three constructs, one as a generic statement of explanation, one for black holes, and one for wormholes, so as to gain a perspective on every kind of influence.

scholarly journals Bulk supertranslation memories: A concept reshaping the vacua and black holes of general relativity

2016 ◽  
Vol 25 (12) ◽  
pp. 1644006 ◽  
Author(s):  
Geoffrey Compère
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Memory Effect ◽  
Null Infinity ◽  
Asymptotically Flat ◽  
Fundamental Symmetry ◽  
Geometrical Features ◽  
Flat Spacetimes ◽  
Future Null Infinity

The memory effect is a prediction of general relativity on the same footing as the existence of gravitational waves. The memory effect is understood at future null infinity as a transition induced by null radiation from a Poincaré vacuum to another vacuum. Those are related by a supertranslation, which is a fundamental symmetry of asymptotically flat spacetimes. In this paper, I argue that finite supertranslation diffeomorphisms should be extended into the bulk spacetime consistently with canonical charge conservation. It then leads to fascinating geometrical features of gravitational Poincaré vacua. I then argue that in the process of black hole merger or gravitational collapse, dramatic but computable memory effects occur. They lead to a final stationary metric which qualitatively deviates from the Schwarzschild metric.

scholarly journals BMS field theories and Weyl anomaly

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Arjun Bagchi ◽  
Sudipta Dutta ◽  
Kedar S. Kolekar ◽  
Punit Sharma
Keyword(s):  
Three Dimensions ◽  
Field Theories ◽  
Partition Functions ◽  
Two Dimensional ◽  
Speed Of Light ◽  
Asymptotically Flat ◽  
Weyl Invariance ◽  
Flat Spacetimes ◽  
Liouville Action ◽  
Null Surfaces

Abstract Two dimensional field theories with Bondi-Metzner-Sachs symmetry have been proposed as duals to asymptotically flat spacetimes in three dimensions. These field theories are naturally defined on null surfaces and hence are conformal cousins of Carrollian theories, where the speed of light goes to zero. In this paper, we initiate an investigation of anomalies in these field theories. Specifically, we focus on the BMS equivalent of Weyl invariance and its breakdown in these field theories and derive an expression for Weyl anomaly. Considering the transformation of partition functions under this symmetry, we derive a Carrollian Liouville action different from ones obtained in the literature earlier.

scholarly journals Islands and stretched horizon

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Yoshinori Matsuo
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hawking Radiation ◽  
Entanglement Entropy ◽  
Total System ◽  
Island Rule ◽  
Asymptotically Flat ◽  
Flat Spacetime ◽  
Ads Spacetime ◽  
Hole Geometry

Abstract Recently it was proposed that the entanglement entropy of the Hawking radiation contains the information of a region including the interior of the event horizon, which is called “island.” In studies of the entanglement entropy of the Hawking radiation, the total system in the black hole geometry is separated into the Hawking radiation and black hole. In this paper, we study the entanglement entropy of the black hole in the asymptotically flat Schwarzschild spacetime. Consistency with the island rule for the Hawking radiation implies that the information of the black hole is located in a different region than the island. We found an instability of the island in the calculation of the entanglement entropy of the region outside a surface near the horizon. This implies that the region contains all the information of the total system and the information of the black hole is localized on the surface. Thus the surface would be interpreted as the stretched horizon. This structure also resembles black holes in the AdS spacetime with an auxiliary flat spacetime, where the information of the black hole is localized at the interface between the AdS spacetime and the flat spacetime.

scholarly journals Soft photon theorem in the small negative cosmological constant limit

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Nabamita Banerjee ◽  
Karan Fernandes ◽  
Arpita Mitra
Keyword(s):  
Cosmological Constant ◽  
Tree Level ◽  
Leading Order ◽  
Asymptotically Flat ◽  
Soft Factor ◽  
Flat Spacetime ◽  
Electromagnetic Interactions ◽  
Flat Spacetimes ◽  
Perturbative Corrections ◽  
Soft Factors

Abstract We study the effect of electromagnetic interactions on the classical soft theorems on an asymptotically AdS background in 4 spacetime dimensions, in the limit of a small cosmological constant or equivalently a large AdS radius l. This identifies 1/l2 perturbative corrections to the known asymptotically flat spacetime leading and subleading soft factors. Our analysis is only valid to leading order in 1/l2. The leading soft factor can be expected to be universal and holds beyond tree level. This allows us to derive a 1/l2 corrected Ward identity, following the known equivalence between large gauge Ward identities and soft theorems in asymptotically flat spacetimes.

scholarly journals Thermodynamically stable asymptotically flat hairy black holes with a dilaton potential

2019 ◽  
Vol 2019 (3) ◽  
Author(s):  
Dumitru Astefanesei ◽  
David Choque ◽  
Francisco Gómez ◽  
Raúl Rojas
Keyword(s):  
Black Holes ◽  
Asymptotically Flat ◽  
Hairy Black Holes
Sign in / Sign up

Export Citation Format

Share Document