scholarly journals Black hole interactions at large D: brane blobology

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Ryotaku Suzuki
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dynamical Theory ◽  
Effective Theory ◽  
Black Brane ◽  
Linear Dynamics ◽  
Effective Force ◽  
Einstein's Equation ◽  
Perturbative Regime ◽  
Axisymmetric Solutions

Abstract In the large dimension (D) limit, Einstein’s equation reduces to an effective theory on the horizon surface, drastically simplifying the black hole analysis. Especially, the effective theory on the black brane has been successful in describing the non-linear dynamics not only of black branes, but also of compact black objects which are encoded as solitary Gaussian-shaped lumps, blobs. For a rigidly rotating ansatz, in addition to axisymmetric deformed branches, various non-axisymmetric solutions have been found, such as black bars, which only stay stationary in the large D limit.In this article, we demonstrate the blob approximation has a wider range of applicability by formulating the interaction between blobs and subsequent dynamics. We identify that this interaction occurs via thin necks connecting blobs. Especially, black strings are well captured in this approximation sufficiently away from the perturbative regime. Highly deformed black dumbbells and ripples are also found to be tractable in the approximation. By defining the local quantities, the effective force acting on distant blobs are evaluated as well. These results reveal that the large D effective theory is capable of describing not only individual black holes but also the gravitational interactions between them, as a full dynamical theory of interactive blobs, which we call brane blobology.

scholarly journals NONCOMMUTATIVE BLACK HOLES, THE FINAL APPEAL TO QUANTUM GRAVITY: A REVIEW

2009 ◽  
Vol 24 (07) ◽  
pp. 1229-1308 ◽  
Author(s):  
PIERO NICOLINI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Effective Theory ◽  
Final State ◽  
Curved Space ◽  
Higher Dimensional ◽  
Energy Hadron ◽  
Black Hole Remnant ◽  
First Time

We present the state of the art regarding the relation between the physics of Quantum Black Holes and Noncommutative Geometry. We start with a review of models proposed in the literature for describing deformations of General Relativity in the presence of noncommutativity, seen as an effective theory of Quantum Gravity. We study the resulting metrics, proposed to replace or at least to improve the conventional black hole solutions of Einstein's equation. In particular, we analyze noncommutative-inspired solutions obtained in terms of quasiclassical noncommutative coordinates: indeed because of their surprising new features, these solutions enable us to circumvent long standing problems with Quantum Field Theory in Curved Space and to cure the singular behavior of gravity at the centers of black holes. As a consequence, for the first time, we get a complete description of what we may call the black hole SCRAM, the shut down of the emission of thermal radiation from the black hole: in place of the conventional scenario of runaway evaporation in the Planck phase, we find a zero temperature final state, a stable black hole remnant, whose size and mass are determined uniquely in terms of the noncommutative parameter θ. This result turns out to be of vital importance for the physics of the forthcoming experiments at the LHC, where mini black hole production is foreseen in extreme energy hadron collisions. Because of this, we devote the final part of this review to higher-dimensional solutions and their phenomenological implications for TeV Gravity.

scholarly journals WHAT DID WE LEARN FROM STUDYING ACOUSTIC BLACK HOLES?

2002 ◽  
Vol 17 (20) ◽  
pp. 2721-2725 ◽  
Author(s):  
RENAUD PARENTANI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hawking Radiation ◽  
Asymptotic Properties ◽  
Planck Scale ◽  
Density Fluctuations ◽  
Effective Theory ◽  
Linear Dispersion ◽  
Black Hole Evaporation ◽  
Acoustic Black Holes

The study of acoustic black holes has been undertaken to provide new insights about the role of high frequencies in black hole evaporation. Because of the infinite gravitational redshift from the event horizon, Hawking quanta emerge from configurations which possessed ultra high (trans-Planckian) frequencies. Therefore Hawking radiation cannot be derived within the framework of a low energy effective theory; and in all derivations there are some assumptions concerning Planck scale physics. The analogy with condensed matter physics was thus introduced to see if the asymptotic properties of the Hawking phonons emitted by an acoustic black hole, namely stationarity and thermality, are sensitive to the high frequency physics which stems from the granular character of matter and which is governed by a non-linear dispersion relation. In 1995 Unruh showed that they are not sensitive in this respect, in spite of the fact that phonon propagation near the (acoustic) horizon drastically differs from that of photons. In 2000 the same analogy was used to establish the robustness of the spectrum of primordial density fluctuations in inflationary models. This analogy is currently stimulating research for experimenting Hawking radiation. Finally it could also be a useful guide for going beyond the semi-classical description of black hole evaporation.

scholarly journals Squashed black holes at large D

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Ryotaku Suzuki ◽  
Shinya Tomizawa
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Static Solution ◽  
Flow Equation ◽  
Effective Theory ◽  
Theory Approach ◽  
First Order ◽  
Extremal Limit ◽  
Horizon Geometry ◽  
Kaluza Klein

Abstract Using the large D effective theory approach, we construct a static solution of non-extremal and squashed black holes with/without an electric charge, which describes a spherical black hole in a Kaluza-Klein spacetime with a compactified dimension. The asymptotic background with a compactified dimension and near-horizon geometry are analytically solved by the 1/D expansion. Particularly, our work demonstrates that the large D limit can be applied to solve the non-trivial background with a compactified direction, which leads to a first-order flow equation. Moreover, we show that the extremal limit consistently reproduces the known extremal result.

scholarly journals Rotating 5D black holes: Interactions and deformations near extremality

2021 ◽  
Vol 11 (6) ◽  
Author(s):  
Alejandra Castro ◽  
Juan Pedraza ◽  
Chiara Toldo ◽  
Evita Verheijden
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Degrees Of Freedom ◽  
Effective Theory ◽  
Extremal Black Hole ◽  
Massive Scalar Field ◽  
Five Dimensions ◽  
Interesting Insight ◽  
Angular Momenta ◽  
Horizon Geometry

We study a two-dimensional theory of gravity coupled to matter that is relevant to describe holographic properties of black holes with two equal angular momenta in five dimensions (with or without cosmological constant). We focus on the near-horizon geometry of the near-extremal black hole, where the effective theory reduces to Jackiw-Teitelboim (JT) gravity coupled to a massive scalar field. We compute the corrections to correlation functions due to cubic interactions present in this theory. A novel feature is that these corrections do not have a definite sign: for AdS_55 black holes the sign depends on the mass of the extremal solution. We discuss possible interpretations of these corrections from a gravitational and holographic perspective. We also quantify the imprint of the JT sector on the UV region, i.e. how these degrees of freedom, characteristic for the near-horizon region, influence the asymptotically far region of the black hole. This gives an interesting insight on how to interpret the IR modes in the context of their UV completion, which depends on the environment that contains the black hole.

scholarly journals Entropy production and entropic attractors in black hole fusion and fission

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Tomás Andrade ◽  
Roberto Emparan ◽  
Aron Jansen ◽  
David Licht ◽  
Raimon Luna ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Entropy Production ◽  
Black Hole Entropy ◽  
Effective Theory ◽  
Small Subset ◽  
Entropy Maximization ◽  
Good Guide ◽  
Black Strings ◽  
The Stability

Abstract We study how black hole entropy is generated and the role it plays in several highly dynamical processes: the decay of unstable black strings and ultraspinning black holes; the fusion of two rotating black holes; and the subsequent fission of the merged system into two black holes that fly apart (which can occur in dimension D ≥ 6, with a mild violation of cosmic censorship). Our approach uses the effective theory of black holes at D → ∞, but we expect our main conclusions to hold at finite D. Black hole fusion is highly irreversible, while fission, which follows the pattern of the decay of black strings, generates comparatively less entropy. In 2 → 1 → 2 black hole collisions an intermediate, quasi-thermalized state forms that then fissions. This intermediate state erases much of the memory of the initial states and acts as an attractor funneling the evolution of the collision towards a small subset of outgoing parameters, which is narrower the closer the total angular momentum is to the critical value for fission. Entropy maximization provides a very good guide for predicting the final outgoing states. Along our study, we clarify how entropy production and irreversibility appear in the large D effective theory. We also extend the study of the stability of new black hole phases (black bars and dumbbells). Finally, we discuss entropy production through charge diffusion in collisions of charged black holes.

scholarly journals BLACK HOLE GEOMETRIES IN NONCOMMUTATIVE STRING THEORY

2006 ◽  
Vol 21 (30) ◽  
pp. 6087-6114 ◽  
Author(s):  
SUPRIYA KAR ◽  
SUMIT MAJUMDAR
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gauge Theory ◽  
String Theory ◽  
Hawking Radiation ◽  
Effective Theory ◽  
Effective Gravity ◽  
Noncommutative Gauge Theory ◽  
Em Field ◽  
Hole Geometry

We obtain a generalized Schwarzschild (GS) and a generalized Reissner–Nordstrom (GRN) black hole geometries in 3+1 dimensions, in a noncommutative string theory. In particular, we consider an effective theory of gravity on a curved D3-brane in presence of an electromagnetic (EM) field. Two different length scales, inherent in its noncommutative counterpart, are exploited to obtain a theory of effective gravity coupled to an U(1) noncommutative gauge theory to all orders in Θ. It is shown that the GRN-black hole geometry, in the Planckian regime, reduces to the GS-black hole. However in the classical regime it may be seen to govern both the Reissner–Nordstrom and the Schwarzschild geometries. The emerging notion of 2D black holes evident in the framework are analyzed. It is argued that the D-string in the theory may be described by the near horizon 2D black hole geometry, in the gravity decoupling limit. Finally, our analysis explains the nature of the effective force derived from the nonlinear EM-field and accounts for the Hawking radiation phenomenon in the formalism.

scholarly journals Effective Field Theory for the perturbations of a slowly rotating black hole

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Lam Hui ◽  
Alessandro Podo ◽  
Luca Santoni ◽  
Enrico Trincherini
Keyword(s):  
Field Theory ◽  
Black Holes ◽  
Black Hole ◽  
Effective Field Theory ◽  
Effective Field ◽  
Effective Theory ◽  
Order Unity ◽  
Rotating Black Hole ◽  
Scalar Hair ◽  
Parity Breaking

Abstract We develop the effective theory for perturbations around black holes with scalar hair, in two directions. First, we show that the scalar-Gauss-Bonnet theory, often used as an example exhibiting scalar black hole hair, can be deformed by galileon operators leading to order unity changes to its predictions. The effective theory for perturbations thus provides an efficient framework for describing and constraining broad classes of scalar-tensor theories, of which the addition of galileon operators is an example. Second, we extend the effective theory to perturbations around an axisymmetric, slowly rotating black hole, at linear order in the black hole spin. We also discuss the inclusion of parity-breaking operators in the effective theory.

scholarly journals Morphological evolution of supermassive black hole merger hosts and multimessenger signatures

2021 ◽  
Vol 503 (3) ◽  
pp. 3629-3642
Author(s):  
Colin DeGraf ◽  
Debora Sijacki ◽  
Tiziana Di Matteo ◽  
Kelly Holley-Bockelmann ◽  
Greg Snyder ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Star Formation ◽  
Morphological Evolution ◽  
Full Range ◽  
High Mass ◽  
Morphological Evidence ◽  
Galaxy Mergers ◽  
Host Galaxies ◽  
Supermassive Black Hole

ABSTRACT With projects such as Laser Interferometer Space Antenna (LISA) and Pulsar Timing Arrays (PTAs) expected to detect gravitational waves from supermassive black hole mergers in the near future, it is key that we understand what we expect those detections to be, and maximize what we can learn from them. To address this, we study the mergers of supermassive black holes in the Illustris simulation, the overall rate of mergers, and the correlation between merging black holes and their host galaxies. We find these mergers occur in typical galaxies along the MBH−M* relation, and that between LISA and PTAs we expect to probe the full range of galaxy masses. As galaxy mergers can trigger star formation, we find that galaxies hosting low-mass black hole mergers tend to show a slight increase in star formation rates compared to a mass-matched sample. However, high-mass merger hosts have typical star formation rates, due to a combination of low gas fractions and powerful active galactic nucleus feedback. Although minor black hole mergers do not correlate with disturbed morphologies, major mergers (especially at high-masses) tend to show morphological evidence of recent galaxy mergers which survive for ∼500 Myr. This is on the same scale as the infall/hardening time of merging black holes, suggesting that electromagnetic follow-ups to gravitational wave signals may not be able to observe this correlation. We further find that incorporating a realistic time-scale delay for the black hole mergers could shift the merger distribution towards higher masses, decreasing the rate of LISA detections while increasing the rate of PTA detections.

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 Epicyclic Oscillations around Simpson–Visser Regular Black Holes and Wormholes

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 279
Author(s):  
Zdeněk Stuchlík ◽  
Jaroslav Vrba
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Observational Data ◽  
High Frequency ◽  
Galactic Nuclei ◽  
Supermassive Black Holes ◽  
Periodic Oscillations ◽  
High Length ◽  
Circular Geodesic

We study epicyclic oscillatory motion along circular geodesics of the Simpson–Visser meta-geometry describing in a unique way regular black-bounce black holes and reflection-symmetric wormholes by using a length parameter l. We give the frequencies of the orbital and epicyclic motion in a Keplerian disc with inner edge at the innermost circular geodesic located above the black hole outer horizon or on the our side of the wormhole. We use these frequencies in the epicyclic resonance version of the so-called geodesic models of high-frequency quasi-periodic oscillations (HF QPOs) observed in microquasars and around supermassive black holes in active galactic nuclei to test the ability of this meta-geometry to improve the fitting of HF QPOs observational data from the surrounding of supermassive black holes. We demonstrate that this is really possible for wormholes with sufficiently high length parameter l.

Sign in / Sign up

Export Citation Format

Share Document