共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
The AdS
5 black hole space-time with perturbed dilaton field background considered. We use the holographic AdS/QCD soft-wall model
to investigate the wave functions and the effective potential. In this model, glueballs are described by a massless scalar
field in an AdS
5 black hole with a dilaton soft-wall background. For the first time we use modified dilaton field and discuss the consequence
of the perturbation. In order to obtain the effective potential we rewrite the equation of motion in the Schr?dinger like
equation, then try to find corresponding solution. 相似文献
3.
We compute exactly the semi-classical radiation spectrum for a class of non-asymptotically flat charged dilaton black holes, the so-called linear dilaton black holes. In the high frequency regime, the temperature for these black holes generically agrees with the surface gravity result. In the special case where the black hole is massless, we show that, although the surface gravity remains finite, there is no radiation, in agreement with the fact that massless objects cannot radiate. 相似文献
4.
We consider the metric exterior to a charged dilaton black hole in a de Sitter universe. We study the motion of a test particle
in this metric. Conserved quantities are identified and the Hamilton–Jacobi method is employed for the solutions of the equations
of motion. At large distances from the black hole the Hubble expansion of the universe modifies the effective potential such
that bound orbits could exist up to an upper limit of the angular momentum per mass for the orbiting test particle. We then
study the phenomenon of strong field gravitational lensing by these black holes by extending the standard formalism of strong
lensing to the non-asymptotically flat dilaton-de Sitter metric. Expressions for the various lensing quantities are obtained
in terms of the metric coefficients. 相似文献
5.
Z. Dayyani A. Sheykhi M. H. Dehghani S. Hajkhalili 《The European Physical Journal C - Particles and Fields》2018,78(2):152
In this paper, we take into account the dilaton black hole solutions of Einstein gravity in the presence of logarithmic and exponential forms of nonlinear electrodynamics. First of all, we consider the cosmological constant and nonlinear parameter as thermodynamic quantities which can vary. We obtain thermodynamic quantities of the system such as pressure, temperature and Gibbs free energy in an extended phase space. We complete the analogy of the nonlinear dilaton black holes with the Van der Waals liquid–gas system. We work in the canonical ensemble and hence we treat the charge of the black hole as an external fixed parameter. Moreover, we calculate the critical values of temperature, volume and pressure and show that they depend on the dilaton coupling constant as well as on the nonlinear parameter. We also investigate the critical exponents and find that they are universal and independent of the dilaton and nonlinear parameters, which is an expected result. Finally, we explore the phase transition of nonlinear dilaton black holes by studying the Gibbs free energy of the system. We find that in the case of \(T>T_c\), we have no phase transition. When \(T=T_c\), the system admits a second-order phase transition, while for \(T=T_\mathrm{f}<T_c\) the system experiences a first-order transition. Interestingly, for \(T_\mathrm{f}<T<T_c\) we observe a zeroth-order phase transition in the presence of a dilaton field. This novel zeroth-order phase transition occurs due to a finite jump in the Gibbs free energy which is generated by the dilaton–electromagnetic coupling constant, \(\alpha \), for a certain range of pressure. 相似文献
6.
We investigate extremal charged black hole solutions in the four-dimensional string frame Gauss-Bonnet gravity with the Maxwell
field and the dilaton. Without curvature corrections, the extremal electrically charged dilatonic black holes have singular
horizon and zero Bekenstein entropy. When the Gauss-Bonnet term is switched on, the horizon radius expands to a finite value
provided curvature corrections are strong enough. Below a certain threshold value of the Gauss-Bonnet coupling the extremal
black hole solutions cease to exist. Since decreasing Gauss-Bonnet coupling corresponds to decreasing string coupling g
s
, the situation can tentatively be interpreted as classical indication on the black hole—string transition. Previously the
extremal dilaton black holes were studied in the Einstein-frame version of the Gauss-Bonnet gravity. Here we work in the string
frame version of the theory with the S-duality symmetric dilaton function as required by the heterotic string theory.
The article is published in the original. 相似文献
7.
The Klein-Gordon equation is applied to investigate superradiance around a dilatonic variant of dyonic black holes, a type of black holes whose extremal limits are justified for the S-wave approximation. The result is: The dilaton field boosts the superradiance. 相似文献
8.
Using coupled harmonic oscillators model, we numerical analyze the entanglement entropy of massless scalar field in Gafinkle–Horowitz–Strominger (GHS) dilaton spacetime and Gibbons–Maeda (GM) dilaton spacetime. By numerical fitting, we find that the entanglement entropy of the dilaton black holes receive contribution from dilaton charge and is proportional to the area of the event horizon. It is interesting to note that the results of numerical fitting are coincide with ones obtained by using brick wall method and Euclidean path integral approach. 相似文献
9.
Jiliang Jing 《International Journal of Theoretical Physics》2000,39(6):1687-1696
The quantum correction to the entropy of four-dimensional nonextreme static,spherically symmetric dilaton black holes arising from electromagnetic fields isinvestigated by 't Hooft's brick wall model. The Garfinkle-Horowitz-Strominger,Gibbons-Maeda, and Garfinkle-Horne dilaton black holes areconsidered. It is shown that the one-loop quantum correction arising from theelectromagnetic fields is exactly twice that due to a massless scalar field. Theresult agrees with that of the Schwarzschild and Reissner-Nordström blackholes. 相似文献
10.
The Bohr–Sommerfeld quantization rule is useful to study the area spectrum of black holes by employing adiabatic invariants. This method is extended to charged dilaton black holes in 2 $+$ + 1 dimensions. We put the background space-time into the Kruskal-like coordinate to find the period with respect to Euclidian time. Also assuming that the adiabatic invariant obeys Bohr–Sommerfeld quantization rule, detailed study of area and entropy spectrum has been done. It is dependent on the charge and is equally spaced as well. We also investigate the thermodynamics of the charged dilaton black hole. 相似文献
11.
We studied the influence of dilaton field on the dynamical collapse of a charged scalar one. Different values of the initial amplitude of dilaton field as well as the altered values of the dilatonic coupling constant were considered. We described structures of spacetimes and properties of black holes emerging from the collapse of electrically charged scalar field in dilaton gravity. Moreover, we provided a meaningful comparison of the collapse in question with the one in Einstein gravity, when dilaton field is absent and its coupling with the scalar field is equal to zero. The course and results of the dynamical collapse process seem to be very sensitive to the amplitude of dilaton field and to the value of the coupling constant in the underlying theory. 相似文献
12.
Burkhard Kleihaus Jutta Kunz Francisco Navarro-Lérida Ulrike Neemann 《General Relativity and Gravitation》2008,40(6):1279-1310
We consider globally regular and black hole solutions in SU(2) Einstein–Yang–Mills–Higgs theory, coupled to a dilaton field.
The basic solutions represent magnetic monopoles, monopole–antimonopole systems or black holes with monopole or dipole hair.
When the globally regular solutions carry additionally electric charge, an angular momentum density results, except in the
simplest spherically symmetric case. We evaluate the global charges of the solutions and their effective action, and analyze
their dependence on the gravitational coupling strength. We show, that in the presence of a dilaton field, the black hole
solutions satisfy a generalized Smarr type mass formula.
B. Kleihaus gratefully acknowledges support by the German Aerospace Center.
F. Navarro-Lérida gratefully acknowledges support by the Ministerio de Educación y Ciencia under grant EX2005-0078. 相似文献
13.
It is well known that Hawking radiation can be treated as a quantum tunneling process of particles from the event horizon of black hole. In this paper, we attempt to apply the massive vector bosons tunneling method to study the Hawking radiation from the non-rotating and rotating dilaton black holes. Starting with the Proca field equation that govern the dynamics of massive vector bosons, we derive the tunneling probabilities and radiation spectrums of the emitted vector bosons from the static spherical symmetric dilatonic black hole, the rotating Kaluza-Klein black hole, and the rotating Kerr-Sen black hole. Comparing the results with the blackbody spectrum, we satisfactorily reproduce the Hawking temperatures of these dilaton black holes, which are consistent with the previous results in the literature. 相似文献
14.
The virtual black hole phenomenon, which has been observed previously in specific models, is established for generic 2D dilaton gravity theories with scalar matter. The ensuing effective line element can become asymptotically flat only for two classes of models; among them spherically reduced theories and the string inspired dilaton black hole. We present simple expressions for the lowest order scalar field vertices of the effective theory which one obtains after integrating out geometry exactly. Treating the boundary in a natural and simple way, asymptotic states, tree-level vertices and the tree-level S-matrix are conformally invariant. Examples are provided pinpointing the physical consequences of virtual black holes on the (CPT-invariant) S-matrix for gravitational scattering of scalar particles. For minimally coupled scalars the evaluation of the S-matrix in closed form is straightforward. For a class of theories including the string inspired dilation black hole all tree-graph vertices vanish, which explains the particular simplicity of that model and at the same time shows yet another essential difference to the Schwarzschild case.Received: 7 August 2002, Revised: 2 June 2003, Published online: 11 July 2003D.V. Vassilevich: On leave from V. Fock Institute of Physics, St. Petersburg University, 198904 St. Petersburg, Russia 相似文献
15.
Numerical studies of the coupled Einstein‐Klein‐Gordon system have recently revealed that confined scalar fields generically collapse to form caged black holes. In the light of this finding, we analytically study the characteristic resonance spectra of the confined scalar fields in rotating linear dilaton black hole geometry. Confining mirrors (cage) are assumed to be placed in the near‐horizon region of a caged rotating linear dilaton black hole ( is the radius of the cage and r2 represents the event horizon). The radial part of the Klein‐Gordon equation is written as a Schrödinger‐like wave equation, which reduces to a Bessel differential equation around the event horizon. Using analytical tools and proper boundary conditions, we obtain the boxed‐quasinormal mode frequencies of the caged rotating linear dilaton black hole. Finally, we employ Maggiore's method, which evaluates the transition frequency in the adiabatic invariant quantity from the highly damped quasinormal modes, in order to investigate the entropy/area spectra of the rotating linear dilaton black hole. 相似文献
16.
I. Sakalli M. Halilsoy H. Pasaoglu 《International Journal of Theoretical Physics》2011,50(10):3212-3224
It has been shown recently that information is lost in the Hawking radiation of the linear dilaton black holes in various
theories when applying the tunneling formalism of Parikh and Wilczek without considering quantum gravity effects. In this
paper, we recalculate the emission probability by taking into account the log-area correction to the Bekenstein-Hawking entropy
and the statistical correlation between quanta emitted. The crucial role of the quantum gravity effects on the information
leakage and black hole remnant is highlighted. The entropy conservation of the linear dilaton black holes is discussed in
detail. We also model the remnant as an extreme linear dilaton black hole with a pointlike horizon in order to show that such
a remnant cannot radiate and its temperature becomes zero. In summary, we show that the information can also leak out of the
linear dilaton black holes together with preserving unitarity in quantum mechanics. 相似文献
17.
We consider stationary axially symmetric black holes in SU(2) Einstein-Yang-Mills-dilaton theory. We present a mass formula for these stationary non-Abelian black holes, which also holds for Abelian black holes. The presence of the dilaton field allows for rotating black holes, which possess nontrivial electric and magnetic gauge fields, but do not carry a non-Abelian charge. We further present a new uniqueness conjecture. 相似文献
18.
S. Habib Mazharimousavi M. Halilsoy Z. Amirabi 《General Relativity and Gravitation》2010,42(2):261-280
We find large classes of non-asymptotically flat Einstein–Yang–Mills–Dilaton and Einstein–Yang–Mills–Born–Infeld–Dilaton black
holes in N-dimensional spherically symmetric spacetime expressed in terms of the quasilocal mass. Extension of the dilatonic
YM solution to N-dimensions has been possible by employing the generalized Wu-Yang ansatz. Another metric ansatz, which aided
in finding exact solutions is the functional dependence of the radius function on the dilaton field. These classes of black
holes are stable against linear radial perturbations. In the limit of vanishing dilaton we obtain Bertotti–Robinson type metrics
with the topology of AdS
2×S
N–2. Since connection can be established between dilaton and a scalar field of Brans–Dicke type we obtain black hole solutions
also in the Brans–Dicke–Yang–Mills theory as well. 相似文献
19.
We construct a new analytic solution of Einstein–Born–Infeld-dilaton theory in the presence of Liouville-type potentials for the dilaton field. These solutions describe dilaton black holes with nontrivial topology and nonlinear electrodynamics. Black hole horizons and cosmological horizons in these spacetimes, can be a two-dimensional positive, zero or negative constant curvature surface. The asymptotic behavior of these solutions are neither flat nor (A)dS. We calculate the conserved and thermodynamic quantities of these solutions and verify that these quantities satisfy the first law of black hole thermodynamics. 相似文献
20.
We provide a new type of thin-shell wormhole from the black holes with dilaton and monopole fields. The dilaton and monopole
that built the black holes may supply fuel to construct the wormholes. Several characteristics of this thin-shell wormhole
have been discussed. Finally, we discuss the stability of the thin-shell wormholes with a “phantom-like” equation of state
for the exotic matter at the throat. 相似文献