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

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.

1993 ◽  
Vol 08 (08) ◽  
pp. 697-710 ◽  
Author(s):  
X. SHEN

Recently, models of two-dimensional dilaton gravity have been shown to admit classical black hole solutions that exhibit Hawking radiation at the semiclassical level. These classical and semiclassical analyzes have been performed in conformal gauge. We show in this paper that a similar analysis in the light-cone gauge leads to the same results. Moreover, quantization of matter fields in light-cone gauge can be naturally extended to include quantizing the metric field à la KPZ. We argue that this may provide a new framework to address many issues associated to black hole physics.


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.


1996 ◽  
Vol 11 (39n40) ◽  
pp. 3103-3111 ◽  
Author(s):  
AMIT GHOSH ◽  
JNANADEVA MAHARANA

Four-dimensional heterotic string effective action is known to admit non-rotating electrically and magnetically charged black hole solutions. The partition function and entropy is computed for electrically charged black holes and is vanishing in some extremal limit. For the magnetically charged black holes the entropy is also argued to be vanishing in the same extremal limit when these black hole solutions are related by S-duality transformations.


2011 ◽  
Vol 20 (13) ◽  
pp. 2525-2542 ◽  
Author(s):  
A. LÓPEZ-ORTEGA

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.


2018 ◽  
Vol 27 (07) ◽  
pp. 1850073 ◽  
Author(s):  
M. Dehghani

In the present work, thermodynamics of the new black hole solutions to the four-dimensional Einstein–Maxwell-dilaton gravity theory have been studied. The dilaton potential, as the solution to the scalar field equations, has been constructed out by a linear combination of three Liouville-type potentials. Three new classes of charged dilatonic black hole solutions, as the exact solutions to the coupled equations of gravitational, electromagnetic and scalar fields, have been introduced. The conserved charge and mass of the new black holes have been calculated by utilizing Gauss's electric law and Abbott–Deser mass proposal, respectively. Also, the temperature, entropy and the electric potential of these new classes of charged dilatonic black holes have been calculated, making use of the geometrical approaches. Through a Smarr-type mass formula, the intensive parameters of the black holes have been calculated and validity of the first law of black hole thermodynamics has been confirmed. A thermal stability or phase transition analysis has been performed, making use of the canonical ensemble method. The heat capacity of the new black holes has been calculated and the points of type one- and type two-phase transitions as well as the ranges at which the new charged dilatonic black holes are locally stable have been determined, precisely.


1995 ◽  
Vol 10 (32) ◽  
pp. 4681-4687 ◽  
Author(s):  
HYEON-MIN JOHNG ◽  
HAK-SOO SHIN ◽  
KWANG-SUP SOH

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.


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.


2020 ◽  
Vol 80 (10) ◽  
Author(s):  
M. Dehghani

AbstractThe exact solutions of coupled scalar, electromagnetic and gravitational field equations have been obtained in the framework of Einstein-dilaton gravity theory which is coupled to the Born–Infeld nonlinear electrodynamics. The solutions show that Einstein–Born–Infeld-dilaton gravity theory admits three novel classes of nonlinearly charged black hole solutions with the non-flat and non-AdS asymptotic behavior. Some of the solutions, in addition to the naked singularity, extreme and two-horizon black holes, produce one- and multi-horizon black holes too. The electric charge, mass and other thermodynamic quantities of the black holes have been calculated and it has been proved that they satisfy the standard form of the thermodynamical first law. The black hole local stability has been investigated by use of the canonical ensemble method. Noting the black hole heat capacity the points of type-one and type-two phase transitions and the locally stable black holes have been identified exactly. By use of the thermodynamic geometry, and noting the divergent points of the thermodynamic metric proposed by HEPM, it has been shown that the results of this method are consistent with those of canonical ensemble method. Global stability and Hawking–Page phase transition points have been studied by use of the grand canonical ensemble method and regarding the Gibbs free energy of the black holes. By calculating the Gibbs free energies, we characterized the ranges of horizon radii in which the black holes remain globally stable or prefer the radiation phase.


2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Andres Anabalon ◽  
Dumitru Astefanesei ◽  
Antonio Gallerati ◽  
Mario Trigiante

Abstract In this article we study a family of four-dimensional, $$ \mathcal{N} $$ N = 2 supergravity theories that interpolates between all the single dilaton truncations of the SO(8) gauged $$ \mathcal{N} $$ N = 8 supergravity. In this infinitely many theories characterized by two real numbers — the interpolation parameter and the dyonic “angle” of the gauging — we construct non-extremal electrically or magnetically charged black hole solutions and their supersymmetric limits. All the supersymmetric black holes have non-singular horizons with spherical, hyperbolic or planar topology. Some of these supersymmetric and non-extremal black holes are new examples in the $$ \mathcal{N} $$ N = 8 theory that do not belong to the STU model. We compute the asymptotic charges, thermodynamics and boundary conditions of these black holes and show that all of them, except one, introduce a triple trace deformation in the dual theory.


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