Extracting Hawking radiation near the horizon of AdS black holes

Abstract

We study how the evaporation rate of spherically symmetric black holes is affected through the extraction of radiation close to the horizon. We adopt a model of extraction that involves a perfectly absorptive screen placed close to the horizon and show that the evaporation rate can be changed depending on how close to the horizon the screen is placed. We apply our results to show that the scrambling time defined by the Hayden-Preskill decoding criterion, which is derived in Pennington’s work (arXiv:1905.08255) through entanglement wedge reconstruction is modified. The modifications appear as logarithmic corrections to Pennington’s time scale which depend on where the absorptive screen is placed. By fixing the proper distance between the horizon and screen we show that for small AdS black holes the leading order term in the scrambling time is consistent with Pennington’s scrambling time. However, for large AdS black holes the leading order Log contains the Bekenstein-Hawking entropy of a cell of characteristic length equal to the AdS radius rather than the entropy of the full horizon. Furthermore, using the correspondence between the radial null energy condition (NEC) and the holographic c-theorem, we argue that the screen cannot be arbitrarily close to the horizon. This leads to a holographic argument that black hole mining using a screen cannot significantly alter the lifetime of a black hole.

Æther as an Inevitable Consequence of Quantum Gravity

“…To summarize, the CUM metrics gives a sustained basis for quantum gravity physics, cosmology, and physics of compact astrophysical objects. Although fascinating physics like closed time-like curves [89][90][91], time machines [92,93], wormholes [94], and Hawking radiation [95][96][97] are excluded in the CUM metrics, these metrics give a fresh impetus to investigate the real physical phenomena, including the structure formation [34], CMB [64], the structure of ultracompact astrophysical objects, and search for the decoherence QG effects and other QG consequences from the vacuum fluctuations of the gravitational potential. All these phenomena imply to single out the conformally unimodular metrics corresponding to a reference system, where the aether is at rest "in tote".…”

Entanglement Entropy of Generalized Rindler Wedge

“…Boundary theory interpretation of different bulk wedges. For the same boundary spatial subregion A, we have known that EW encodes all the degrees of freedom of A [15][16][17][18][19][20], while the corresponding CW has been believed not to correspond to EE but encodes the uncertainty left after the observers measure all one-point functions inside the causal domain [41]. Here we propose new boundary interpretations of CW and GRW based on the following facts.…”

“…Another motivation for this work is that gravity is not local, and entanglement wedge (EW) is a natural way to define a spacetime subregion whose degrees of freedom are fully encoded within this subregion [12][13][14][15][16][17][18][19][20]. Our perspective of accelerating observers provides a more general division of spacetime subregions, which are named the generalized Rindler wedges (GRW).…”

Randomly Pruning the Sachdev‐Ye‐Kitaev Model

“…In the context of quantum gravity models, RMT measures of the spectrum serve as somewhat simpler indicators for more complex measures, such as the two‐point correlation function of a Hermitian operator. [ 28–30 ] Investigating whether distinct measures reveal varying facets of quantum chaos and their ability to capture the multifaceted nature of quantum chaos across different systems is a dynamic field of research. Researchers are actively engaged in unraveling the nuanced connections between diverse measures.…”