scholarly journals STRING THEORY ON THREE-DIMENSIONAL BLACK HOLES

1998 ◽  
Vol 13 (08) ◽  
pp. 1229-1262 ◽  
Author(s):  
MAKOTO NATSUUME ◽  
YUJI SATOH
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Three Dimensional ◽  
Matching Condition ◽  
Target Space ◽  
Black Hole Mass ◽  
Curved Space ◽  
Conformal Field ◽  
Black Hole Background

We investigate the string theory on three-dimensional black holes discovered by Bañados, Teitelboim and Zanelli in the framework of conformal field theory. The model is described by an orbifold of the [Formula: see text] WZW model. The spectrum is analyzed by solving the level matching condition and we obtain winding modes. We then study the ghost problem and show explicit examples of physical states with negative norms. We discuss the tachyon propagation and the target space geometry, which are irrelevant to the details of the spectrum. we find a self-dual T-duality transformation reversing the black hole mass. We also discuss difficulties in string theory on curved space–time and possibilities of obtaining a sensible string theory on three-dimensional black holes. This work is the first attempt to quantize a string theory in a black hole background with an infinite number of propagating modes.

MATRIX MODELS AND BLACK HOLES

1993 ◽  
Vol 08 (01) ◽  
pp. 69-78 ◽  
Author(s):  
SUMIT R. DAS
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Matrix Models ◽  
Matrix Model ◽  
Integral Transform ◽  
Two Dimensional ◽  
Black Hole Background

We show that an integral transform of the fluctuations of the collective field of the d=1 matrix model satisfy the same linearized equation as that of the massless “tachyon” in the black hole background of the two-dimensional critical string. This suggests that the d=1 matrix model may provide a non-perturbative description of black holes in two-dimensional string theory.

scholarly journals X-ray properties of reverberation-mapped AGNs with super-Eddington accreting massive black holes

2019 ◽  
Vol 15 (S356) ◽  
pp. 143-143
Author(s):  
Jaya Maithil ◽  
Michael S. Brotherton ◽  
Bin Luo ◽  
Ohad Shemmer ◽  
Sarah C. Gallagher ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Accretion Rate ◽  
Time Lags ◽  
Black Hole Mass ◽  
Host Galaxies ◽  
Massive Black Holes ◽  
X Ray ◽  
Photon Index ◽  
The Impact

AbstractActive Galactic Nuclei (AGN) exhibit multi-wavelength properties that are representative of the underlying physical processes taking place in the vicinity of the accreting supermassive black hole. The black hole mass and the accretion rate are fundamental for understanding the growth of black holes, their evolution, and the impact on the host galaxies. Recent results on reverberation-mapped AGNs show that the highest accretion rate objects have systematic shorter time-lags. These super-Eddington accreting massive black holes (SEAMBHs) show BLR size 3-8 times smaller than predicted by the Radius-Luminosity (R-L) relationship. Hence, the single-epoch virial black hole mass estimates of highly accreting AGNs have an overestimation of a factor of 3-8 times. SEAMBHs likely have a slim accretion disk rather than a thin disk that is diagnostic in X-ray. I will present the extreme X-ray properties of a sample of dozen of SEAMBHs. They indeed have a steep hard X-ray photon index, Γ, and demonstrate a steeper power-law slope, ασx.

scholarly journals Refining the mass estimate for the intermediate-mass black hole candidate in NGC 3319

2021 ◽  
Vol 38 ◽  
Author(s):  
Benjamin L. Davis ◽  
Alister W. Graham
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Meta Analysis ◽  
Rotational Velocity ◽  
Logarithmic Spiral ◽  
Star Cluster ◽  
Black Hole Mass ◽  
Intermediate Mass ◽  
Mass Scaling ◽  
Cluster Mass

Abstract Recent X-ray observations by Jiang et al. have identified an active galactic nucleus (AGN) in the bulgeless spiral galaxy NGC 3319, located just $14.3\pm 1.1$ Mpc away, and suggest the presence of an intermediate-mass black hole (IMBH; $10^2\leq M_\bullet/\textrm{M}_{\odot}\leq 10^5$ ) if the Eddington ratios are as high as 3 to $3\times10^{-3}$ . In an effort to refine the black hole mass for this (currently) rare class of object, we have explored multiple black hole mass scaling relations, such as those involving the (not previously used) velocity dispersion, logarithmic spiral arm pitch angle, total galaxy stellar mass, nuclear star cluster mass, rotational velocity, and colour of NGC 3319, to obtain 10 mass estimates, of differing accuracy. We have calculated a mass of $3.14_{-2.20}^{+7.02}\times10^4\,\textrm{M}_\odot$ , with a confidence of 84% that it is $\leq $ $10^5\,\textrm{M}_\odot$ , based on the combined probability density function from seven of these individual estimates. Our conservative approach excluded two black hole mass estimates (via the nuclear star cluster mass and the fundamental plane of black hole activity—which only applies to black holes with low accretion rates) that were upper limits of ${\sim}10^5\,{\textrm M}_{\odot}$ , and it did not use the $M_\bullet$ – $L_{\textrm 2-10\,\textrm{keV}}$ relation’s prediction of $\sim$ $10^5\,{\textrm M}_{\odot}$ . This target provides an exceptional opportunity to study an IMBH in AGN mode and advance our demographic knowledge of black holes. Furthermore, we introduce our novel method of meta-analysis as a beneficial technique for identifying new IMBH candidates by quantifying the probability that a galaxy possesses an IMBH.

scholarly journals GRAVITY-WAVE DETECTORS AS PROBES OF EXTRA DIMENSIONS

2005 ◽  
Vol 14 (12) ◽  
pp. 2347-2353 ◽  
Author(s):  
CHRIS CLARKSON ◽  
ROY MAARTENS
Keyword(s):  
Black Holes ◽  
String Theory ◽  
Gravity Wave ◽  
Gravity Waves ◽  
Extra Dimensions ◽  
State Of The Art ◽  
Three Dimensional ◽  
Observable Universe ◽  
Dimensional Spacetime ◽  
Higher Dimensional

If string theory is correct, then our observable universe may be a three-dimensional "brane" embedded in a higher-dimensional spacetime. This theoretical scenario should be tested via the state-of-the-art in gravitational experiments — the current and upcoming gravity-wave detectors. Indeed, the existence of extra dimensions leads to oscillations that leave a spectroscopic signature in the gravity-wave signal from black holes. The detectors that have been designed to confirm Einstein's prediction of gravity waves, can in principle also provide tests and constraints on string theory.

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.

A COMMENT ON THE BLACK HOLE INFORMATION PARADOX

2001 ◽  
Vol 16 (supp01c) ◽  
pp. 1001-1004
Author(s):  
SAMIR D. MATHUR
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
String Theory ◽  
Information Paradox ◽  
Loss Of Information ◽  
Black Hole Information ◽  
Classical Gravity ◽  
New Criterion

Results from string theory strongly suggest that formation and evaporation of black holes is a unitary process. Thus we must find a flaw in the semiclassical reasoning that implies a loss of information. We propose a new criterion that limits the domain of classical gravity: the hypersurfaces of a foliation cannot be stretched too much.

scholarly journals ON THE CFT DUALS FOR NEAR-EXTREMAL BLACK HOLES

2011 ◽  
Vol 26 (22) ◽  
pp. 1601-1611 ◽  
Author(s):  
JØRGEN RASMUSSEN
Keyword(s):  
Field Theory ◽  
Black Holes ◽  
Black Hole ◽  
Conformal Field Theory ◽  
Two Dimensional ◽  
Conformal Field ◽  
Horizon Geometry ◽  
Cardy Formula ◽  
Asymptotic Symmetries ◽  
Extremal Black Holes

We consider Kerr–Newman–AdS–dS black holes near extremality and work out the near-horizon geometry of these near-extremal black holes. We identify the exact U (1)L× U (1)R isometries of the near-horizon geometry and provide boundary conditions enhancing them to a pair of commuting Virasoro algebras. The conserved charges of the corresponding asymptotic symmetries are found to be well-defined and nonvanishing and to yield central charges cL≠0 and cR = 0. The Cardy formula subsequently reproduces the Bekenstein–Hawking entropy of the black hole. This suggests that the near-extremal Kerr–Newman–AdS–dS black hole is holographically dual to a non-chiral two-dimensional conformal field theory.

scholarly journals Black hole evaporation in Hořava–Lifshitz gravity

2020 ◽  
Vol 80 (7) ◽  
Author(s):  
Hao Xu ◽  
Yen Chin Ong
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Lorentz Invariance ◽  
Detailed Balance ◽  
Einstein Gravity ◽  
Zero Temperature ◽  
Black Hole Mass ◽  
Black Hole Evaporation ◽  
Higher Derivative ◽  
Temperature State

Abstract Hořava–Lifshitz (HL) gravity was formulated in hope of solving the non-renormalization problem in Einstein gravity and the ghost problem in higher derivative gravity theories by violating Lorentz invariance. In this work we consider the spherically symmetric neutral AdS black hole evaporation process in HL gravity in various spacetime dimensions d, and with detailed balance violation parameter $$0\leqslant \epsilon ^2\leqslant 1$$0⩽ϵ2⩽1. We find that the lifetime of the black holes under Hawking evaporation is dimensional dependent, with $$d=4,5$$d=4,5 behave differently from $$d\geqslant 6$$d⩾6. For the case of $$\epsilon =0$$ϵ=0, in $$d=4,5$$d=4,5, the black hole admits zero temperature state, and the lifetime of the black hole is always infinite. This phenomenon obeys the third law of black hole thermodynamics, and implies that the black holes become an effective remnant towards the end of the evaporation. As $$d\geqslant 6$$d⩾6, however, the lifetime of black hole does not diverge with any initial black hole mass, and it is bounded by a time of the order of $$\ell ^{d-1}$$ℓd-1, similar to the case of Schwarzschild-AdS in Einstein gravity (which corresponds to $$\epsilon ^2=1$$ϵ2=1), though for the latter this holds for all $$d\geqslant 4$$d⩾4. The case of $$0<\epsilon ^2<1$$0<ϵ2<1 is also qualitatively similar with $$\epsilon =0$$ϵ=0.

scholarly journals The Sub-Eddington Boundary for the Quasar Mass–Luminosity Plane: A Theoretical Perspective

Universe ◽  
2019 ◽  
Vol 5 (6) ◽  
pp. 145 ◽  
Author(s):  
David Garofalo ◽  
Damian J. Christian ◽  
Andrew M. Jones
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Survey Data ◽  
Theoretical Perspective ◽  
Sloan Digital Sky Survey ◽  
Black Hole Mass ◽  
Massive Black Holes ◽  
Sky Survey ◽  
Data Release ◽  
Gap Paradigm

By exploring more than sixty thousand quasars from the Sloan Digital Sky Survey Data Release 5, Steinhardt & Elvis discovered a sub-Eddington boundary and a redshift-dependent drop-off at higher black hole mass, possible clues to the growth history of massive black holes. Our contribution to this special issue of Universe amounts to an application of a model for black hole accretion and jet formation to these observations. For illustrative purposes, we include ~100,000 data points from the Sloan Digital Sky Survey Data Release 7 where the sub-Eddington boundary is also visible and propose a theoretical picture that explains these features. By appealing to thin disk theory and both the lower accretion efficiency and the time evolution of jetted quasars compared to non-jetted quasars in our “gap paradigm”, we explain two features of the sub-Eddington boundary. First, we show that a drop-off on the quasar mass-luminosity plane for larger black hole mass occurs at all redshifts. But the fraction of jetted quasars is directly related to the merger function in this paradigm, which means the jetted quasar fraction drops with decrease in redshift, which allows us to explain a second feature of the sub-Eddington boundary, namely a redshift dependence of the slope of the quasar mass–luminosity boundary at high black hole mass stemming from a change in radiative efficiency with time. We are able to reproduce the mass dependence of, as well as the oscillating behavior in, the slope of the sub-Eddington boundary as a function of time. The basic physical idea involves retrograde accretion occurring only for a subset of the more massive black holes, which implies that most spinning black holes in our model are prograde accretors. In short, this paper amounts to a qualitative overview of how a sub-Eddington boundary naturally emerges in the gap paradigm.

Chiral modular bootstrap

2019 ◽  
Vol 34 (28) ◽  
pp. 1950168 ◽  
Author(s):  
M. Ashrafi
Keyword(s):  
Black Hole ◽  
Upper Bound ◽  
Three Dimensional ◽  
Conformal Weight ◽  
Two Dimensional ◽  
Btz Black Hole ◽  
Conformal Field ◽  
Dimensional Gravity ◽  
Large Spin ◽  
Dimension Ratio

Using modular bootstrap we show the lightest primary fields of a unitary compact two-dimensional conformal field theory (with [Formula: see text], [Formula: see text]) has a conformal weight [Formula: see text]. This implies that the upper bound on the dimension of the lightest primary fields depends on their spin. In particular if the set of lightest primary fields includes extremal or near extremal states whose spin to dimension ratio [Formula: see text], the corresponding dimension is [Formula: see text]. From AdS/CFT correspondence, we obtain an upper bound on the spectrum of black hole in three-dimensional gravity. Our results show that if the first primary fields have large spin, the corresponding three-dimensional gravity has extremal or near extremal BTZ black hole.

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