scholarly journals BLACK HOLES IN TWO-DIMENSIONAL DILATON GRAVITY AND NONLINEAR KLEIN-GORDON SOLITON

1995 ◽  
Vol 10 (32) ◽  
pp. 4681-4687 ◽  
Author(s):  
HYEON-MIN JOHNG ◽  
HAK-SOO SHIN ◽  
KWANG-SUP SOH
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Classical Solution ◽  
Matter Field ◽  
Two Dimensional ◽  
Dilaton Gravity ◽  
Hole Formation ◽  
Klein Gordon ◽  
Quartic Interaction ◽  
Interaction Term

Two-dimensional dilaton gravity coupled to a Klein-Gordon matter field with a quartic interaction term is considered. The theory has a classical solution which exhibits black hole formation by a soliton. The geometry of a black hole induced by a soliton is investigated.

scholarly journals WEYL INVARIANCE AND SPURIOUS BLACK HOLES IN TWO-DIMENSIONAL DILATON GRAVITY

1994 ◽  
Vol 09 (27) ◽  
pp. 4811-4835 ◽  
Author(s):  
TAKANORI FUJIWARA ◽  
YUJI IGARASHI ◽  
JISUKE KUBO
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hawking Radiation ◽  
Gravity Models ◽  
Conformal Anomaly ◽  
Quantum Level ◽  
Two Dimensional ◽  
Dilaton Gravity ◽  
Matter Coupling ◽  
Weyl Invariance

In two-dimensional dilaton gravity theories, there may exist a global Weyl invariance which makes the black hole spurious. If the global invariance and the local Weyl invariance of the matter coupling are intact at the quantum level, there is no Hawking radiation. We explicitly verify the absence of anomalies in these symmetries for the model proposed by Callan, Giddings, Harvey and Strominger. The crucial observation is that the conformal anomaly can be cohomologically trivial and so not truly anomalous in such dilaton gravity models.

scholarly journals DUALITIES OF LORENTZIAN AND EUCLIDEAN BLACK HOLES IN TWO-DIMENSIONAL STRING GENERATED MODELS

1995 ◽  
Vol 10 (05) ◽  
pp. 367-378 ◽  
Author(s):  
M. CADONI ◽  
S. MIGNEMI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Heterotic String ◽  
Two Dimensional ◽  
Dilaton Gravity ◽  
String Models ◽  
Black Hole Solutions

We discuss the properties of Lorentzian and Euclidean black hole solutions of a generalized two-dimensional dilaton gravity action containing a modulus field, which arises from the compactification of heterotic string models. The duality symmetries of these solutions are also investigated.

scholarly journals ENTROPY SPECTRA OF SINGLE HORIZON BLACK HOLES IN TWO DIMENSIONS

2011 ◽  
Vol 20 (13) ◽  
pp. 2525-2542 ◽  
Author(s):  
A. LÓPEZ-ORTEGA
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Two Dimensions ◽  
Two Dimensional ◽  
Dilaton Gravity ◽  
Asymptotically Flat

The Hod conjecture proposes that the asymptotic quasinormal frequencies determine the entropy quantum of a black hole. Considering the Maggiore modification of this conjecture, we calculate the entropy spectra of general, single horizon, asymptotically flat black holes in two-dimensional dilaton gravity. We also compute the entropy quanta of the two-dimensional Witten and AdS2 black holes. Using the results for the entropy quanta of these two-dimensional black holes, we discuss whether the produced values are generic. Finally we extend the results on the entropy spectra of other black holes.

scholarly journals Quasinormal Frequencies of a Two-Dimensional Asymptotically Anti-de Sitter Black Hole of the Dilaton Gravity Theory

2021 ◽  
Vol 8 ◽  
Author(s):  
M. I. Hernández-Velázquez ◽  
A. López-Ortega
Keyword(s):  
Black Hole ◽  
Differential Equations ◽  
Iteration Method ◽  
Gravity Theory ◽  
Asymptotic Iteration Method ◽  
Two Dimensional ◽  
Dilaton Gravity ◽  
De Sitter ◽  
Second Order Differential Equations ◽  
Klein Gordon

We numerically calculate the quasinormal frequencies of the Klein-Gordon and Dirac fields propagating in a two-dimensional asymptotically anti-de Sitter black hole of the dilaton gravity theory. For the Klein-Gordon field we use the Horowitz-Hubeny method and the asymptotic iteration method for second order differential equations. For the Dirac field we first exploit the Horowitz-Hubeny method. As a second method, instead of using the asymptotic iteration method for second order differential equations, we propose to take as a basis its formulation for coupled systems of first order differential equations. For the two fields we find that the results that produce the two numerical methods are consistent. Furthermore for both fields we obtain that their quasinormal modes are stable and we compare their quasinormal frequencies to analyze whether their spectra are isospectral. Finally we discuss the main results.

scholarly journals BLACK HOLE FORMATION IN BIDIMENSIONAL DILATON GRAVITY COUPLED TO SCALAR MATTER SYSTEMS

1999 ◽  
Vol 14 (39) ◽  
pp. 2687-2694 ◽  
Author(s):  
M. ALVES ◽  
D. BAZEIA ◽  
V. B. BEZERRA
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Scalar Fields ◽  
The Other ◽  
Gravity Models ◽  
Fourth Power ◽  
Dilaton Gravity ◽  
Hole Formation ◽  
Scalar Matter ◽  
Matter Fields

This work deals with the formation of black hole in bidimensional dilaton gravity coupled to scalar matter fields. We investigate two scalar matter systems, one described by a sixth power potential and the other defined with two scalar fields containing up to the fourth power in the fields. The topological solutions that appear in these cases allow the formation of black holes in the corresponding dilaton gravity models.

scholarly journals On thermodynamics of 2D black holes in brane inflationary potentials

2014 ◽  
Vol 11 (05) ◽  
pp. 1450047 ◽  
Author(s):  
A. Belhaj ◽  
M. Chabab ◽  
H. El Moumni ◽  
M. B. Sedra ◽  
A. Segui
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Solution ◽  
Brane World ◽  
Two Dimensional ◽  
Dilaton Gravity ◽  
De Sitter ◽  
Asymptotic Behaviors ◽  
Dimensional Black Hole ◽  
Hole Geometry

Inspired from the inflation brane world cosmology, we study the thermodynamics of a black hole solution in two-dimensional dilaton gravity with an arctangent potential background. We first derive the two-dimensional black hole geometry, then we examine its asymptotic behaviors. More precisely, we find that such behaviors exhibit properties appearing in some known cases including the anti-de Sitter and the Schwarzschild black holes. Using the complex path method, we compute the Hawking radiation. The entropy function can be related to the value of the potential at the horizon.

scholarly journals Feeding and feedback from little monsters: AGN in dwarf galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 238-242
Author(s):  
Mar Mezcua
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Early Universe ◽  
Dwarf Galaxies ◽  
Scaling Relations ◽  
Strong Impact ◽  
Hole Formation ◽  
Intermediate Mass ◽  
Black Hole Formation ◽  
Low Mass

AbstractDetecting the seed black holes from which quasars formed is extremely challenging; however, those seeds that did not grow into supermassive should be found as intermediate-mass black holes (IMBHs) of 100 – 105 M⊙ in local dwarf galaxies. The use of deep multiwavelength surveys has revealed that a population of actively accreting IMBHs (low-mass AGN) exists in dwarf galaxies at least out to z ˜3. The black hole occupation fraction of these galaxies suggests that the early Universe seed black holes formed from direct collapse of gas, which is reinforced by the possible flattening of the black hole-galaxy scaling relations at the low-mass end. This scenario is however challenged by the finding that AGN feedback can have a strong impact on dwarf galaxies, which implies that low-mass AGN in dwarf galaxies might not be the untouched relics of the early seed black holes. This has important implications for seed black hole formation models.

scholarly journals Islands in linear dilaton black holes

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Georgios K. Karananas ◽  
Alex Kehagias ◽  
John Taskas
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Entanglement Entropy ◽  
Von Neumann Entropy ◽  
Two Dimensional ◽  
Extremal Case ◽  
Von Neumann ◽  
Dimensional Black Hole ◽  
Linear Dilaton ◽  
Linear Dilaton Black Hole

Abstract We derive a novel four-dimensional black hole with planar horizon that asymptotes to the linear dilaton background. The usual growth of its entanglement entropy before Page’s time is established. After that, emergent islands modify to a large extent the entropy, which becomes finite and is saturated by its Bekenstein-Hawking value in accordance with the finiteness of the von Neumann entropy of eternal black holes. We demonstrate that viewed from the string frame, our solution is the two-dimensional Witten black hole with two additional free bosons. We generalize our findings by considering a general class of linear dilaton black hole solutions at a generic point along the σ-model renormalization group (RG) equations. For those, we observe that the entanglement entropy is “running” i.e. it is changing along the RG flow with respect to the two-dimensional worldsheet length scale. At any fixed moment before Page’s time the aforementioned entropy increases towards the infrared (IR) domain, whereas the presence of islands leads the running entropy to decrease towards the IR at later times. Finally, we present a four-dimensional charged black hole that asymptotes to the linear dilaton background as well. We compute the associated entanglement entropy for the extremal case and we find that an island is needed in order for it to follow the Page curve.

Sign in / Sign up

Export Citation Format

Share Document