scholarly journals Two-dimensional black holes in the limiting curvature theory of gravity

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Valeri P. Frolov ◽  
Andrei Zelnikov

Abstract In this paper we discuss modified gravity models in which growth of the curvature is dynamically restricted. To illustrate interesting features of such models we consider a modification of two-dimensional dilaton gravity theory which satisfies the limiting curvature condition. We show that such a model describes two-dimensional black holes which contain the de Sitter-like core instead of the singularity of the original non-modified theory. In the second part of the paper we study Vaidya type solutions of the model of the limiting curvature theory of gravity and used them to analyse properties of black holes which are created by the collapse of null fluid. We also apply these solutions to study interesting features of a black hole evaporation.

1994 ◽  
Vol 09 (27) ◽  
pp. 4811-4835 ◽  
Author(s):  
TAKANORI FUJIWARA ◽  
YUJI IGARASHI ◽  
JISUKE KUBO

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.


2014 ◽  
Vol 11 (05) ◽  
pp. 1450047 ◽  
Author(s):  
A. Belhaj ◽  
M. Chabab ◽  
H. El Moumni ◽  
M. B. Sedra ◽  
A. Segui

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.


2005 ◽  
Vol 20 (38) ◽  
pp. 2919-2924 ◽  
Author(s):  
MARIANO CADONI ◽  
SALVATORE MIGNEMI

We derive two-dimensional (2D) solutions of a generic dilaton gravity model coupled with matter, which describe D-dimensional static black holes with pointlike sources. The equality between the mass M of the D-dimensional gravitational solution and the mass m of the source can also be preserved at the level of the 2D gravity model.


Universe ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 25 ◽  
Author(s):  
Stanislav Alexeyev ◽  
Maxim Sendyuk

We discuss black hole type solutions and wormhole type ones in the effective gravity models. Such models appear during the attempts to construct the quantum theory of gravity. The mentioned solutions, being, mostly, the perturbative generalisations of well-known ones in general relativity, carry out additional set of parameters and, therefore could help, for example, in the studying of the last stages of Hawking evaporation, in extracting the possibilities for the experimental or observational search and in helping to constrain by astrophysical data.


2012 ◽  
Vol 27 (09) ◽  
pp. 1250048 ◽  
Author(s):  
IBRAHIMA BAH ◽  
LEOPOLDO A. PANDO ZAYAS ◽  
CÉSAR A. TERRERO-ESCALANTE

Using a holographic proposal for the geometric entropy we study its behavior in the geometry of Schwarzschild black holes in global AdSp for p = 3, 4, 5. Holographically, the entropy is determined by a minimal surface. On the gravity side, due to the presence of a horizon on the background, generically there are two solutions to the surfaces determining the entanglement entropy. In the case of AdS3, the calculation reproduces precisely the geometric entropy of an interval of length l in a two-dimensional conformal field theory with periodic boundary conditions. We demonstrate that in the cases of AdS4 and AdS5 the sign of the difference of the geometric entropies changes, signaling a transition. Euclideanization implies that various embedding of the holographic surface are possible. We study some of them and find that the transitions are ubiquitous. In particular, our analysis renders a very intricate phase space, showing, for some ranges of the temperature, up to three branches. We observe a remarkable universality in the type of results we obtain from AdS4 and AdS5.


1998 ◽  
Vol 57 (2) ◽  
pp. 1129-1135 ◽  
Author(s):  
T. Futamase ◽  
M. Hotta ◽  
Y. Itoh

2017 ◽  
Vol 26 (14) ◽  
pp. 1750156 ◽  
Author(s):  
Ahmed Alhamzawi

A study of the shadow cast by rotating black holes in different models of modified gravity is presented. It is shown that the size of the shadow cast depends on the modified gravity model used. The distortions of the shadow cast by modified gravity black holes are investigated and the effects are compared with the distortions cast by Kerr black hole. The shadow of a rotating black hole in modified gravity is found to be similar to the shadow cast by Kerr black hole but with different sizes and distortion effects. The naked singularity by rotating modified gravity black hole is discussed. Finally, it is shown that some modified gravity models can present a considerable contribution to the size of black hole shadow.


2017 ◽  
Vol 96 (2) ◽  
Author(s):  
Antonio De Felice ◽  
Noemi Frusciante ◽  
Georgios Papadomanolakis

1995 ◽  
Vol 10 (05) ◽  
pp. 367-378 ◽  
Author(s):  
M. CADONI ◽  
S. MIGNEMI

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.


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