Behaviour of scalar perturbations of a Reissner-Nordström black hole inside the event horizon

This paper considers general scalar perturbations of a Reissner-Nordstrdöm black hole and examines the qualitative behaviour of these perturbations in the region between and on the inner and outer horizons ( r - ≼ r ≼ r + ). Initial data are specified in terms of the ingoing radiation crossing the outer (event) horizon. The only essential restriction on these data is that the radiation should not die away too slowly on this horizon. The resultant perturbations are shown to be bounded and continuous. It is also shown that if ũ is any retarded null coordinate such that ũ = 0 on the event horizon, then the perturbations tend to zero along lines of constant radius as ũ ↓ 0. In particular, all these properties hold for pertur­bations on the inner horizon. For certain types of scalar field (including the zero rest mass scalar field) perturbations vanish at the crossover point on the inner horizon.

2016 ◽  
Vol 25 (01) ◽  
pp. 1650005 ◽  
Author(s):  
Alireza Allahyari ◽  
Javad T. Firouzjaee ◽  
Reza Mansouri

We study the time evolution of the Misner-Sharp mass and the apparent horizon for gravitational collapse of a massless scalar field in the [Formula: see text] spacetime for both cases of narrow and broad waves by numerically solving the Einstein’s equations coupled to a massless scalar field. This is done by relying on the full dynamics of the collapse including the concept of the dynamical horizon. It turns out that the Misner-Sharp mass is everywhere constant except for a rapid change across a thin shell defined by the density profile of the collapsing wave. By studying the evolution of the apparent horizon, indicating the formation of a black hole at different times we see how asymptotically an event horizon forms. The dependence of the thermalization time on the radius of the initial black hole event horizon is also studied.


2009 ◽  
Vol 18 (01) ◽  
pp. 1-11 ◽  
Author(s):  
R. SINI ◽  
V. C. KURIAKOSE

The behavior of a charged scalar field in the RN black hole space–time is studied using the WKB approximation. In the present work, it is assumed that matter waves can be reflected from the event horizon. Using this effect, the Hawking temperature and the absorption cross section for an RN black hole placed in a charged scalar field are calculated. The absorption cross section σabs is found to be inversely proportional to the square of the Hawking temperature of the black hole.


1986 ◽  
Vol 01 (03) ◽  
pp. 709-729 ◽  
Author(s):  
O.J. KWON ◽  
Y.D. KIM ◽  
Y.S. MYUNG ◽  
B.H. CHO ◽  
Y.J. PARK

For the nontachyonic mass (c<0, µ2<6), we have found that all nonstatic perturbations (odd-, even-parity and scalar perturbations) allow only the real values of frequency k. This means that the black hole in the massive Brans-Dicke theory is classically stable. However, for the tachyonic mass of scalar field (c>0, µ2>6), we find that the massive Brans-Dicke theory is classically unstable. We also emphasize that the potential forms of odd-parity perturbations is simply given by the pure-gravitational perturbations. For the even-parity case, we obtain the same potential just as Zerilli’s case by combining the even-parity gravitational wave and scalar wave. For static perturbations (k=0) and c>0, only the odd- and even-parity cases with L=0, 1 is allowed to avoid exponentially growing modes.


2009 ◽  
Vol 24 (22) ◽  
pp. 1775-1783 ◽  
Author(s):  
LIN KAI ◽  
YANG SHUZHENG

In this paper, we research on the scalar field particles and 1/2 spin fermions tunneling from the event horizon of Bardeen–Vaidya black hole by semiclassical method and general tortoise coordinate transformation, and obtain the Hawking temperature and tunneling rate near the event horizon.


Linear perturbations of black hole models by a variety of fields are considered. Perturbing fields include the zero rest mass scalar field in the case of Reissner-Nordstrom, and gravitational, electromagnetic and zero rest mass scalar perturbation in the case of the Kerr model. The analysis deals with the Ψ 0 components (in the Newman-Penrose (1962) formalism) of non-zero spin fields. The symmetry properties of the models are used to derive the crucial condition th at the field be singular on the inner horizon. This condition is independent of the field propagation equation. Initial data are then given in terms of incoming radiation from f - is shown that there exist wellbehaved initial data sets for which the resultant fields are singular on the inner horizon. It is emphasized that this instability result is dependent only on the global symmetries and causal structure of the models considered, and is independent of the precise nature of the perturbing field.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
I. Sakalli ◽  
G. Tokgoz

Maggiore’s method (MM), which evaluates the transition frequency that appears in the adiabatic invariant from the highly damped quasinormal mode (QNM) frequencies, is used to investigate the entropy/area spectra of the Garfinkle–Horowitz–Strominger black hole (GHSBH). Instead of the ordinary QNMs, we compute the boxed QNMs (BQNMs) that are the characteristic resonance spectra of the confined scalar fields in the GHSBH geometry. For this purpose, we assume that the GHSBH has a confining cavity (mirror) placed in the vicinity of the event horizon. We then show how the complex resonant frequencies of the caged GHSBH are computed using the Bessel differential equation that arises when the scalar perturbations around the event horizon are considered. Although the entropy/area is characterized by the GHSBH parameters, their quantization is shown to be independent of those parameters. However, both spectra are equally spaced.


2000 ◽  
Vol 15 (35) ◽  
pp. 2165-2170
Author(s):  
ZHAO REN ◽  
LICHUN ZHANG ◽  
YUEQIN WU

Under nonspherical coordinates, the free energy and the entropy of a scalar field are calculated in terms of the brick-wall method on the background of a nonasymptotically flat cylindrical black hole. It is shown that the entropy is not only related to the area of an outer horizon but also function of inner horizon at nonasymptotically flat space–time, when a black hole has both inner and outer horizons. Further, the entropy expressed by location parameter of outer and inner horizons approaches zero, when the radiation temperature of a black hole approaches zero. It satisfies the Nernst theorem and can be taken as Planck absolute entropy of a black hole.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
JiJi Fan ◽  
Zhong-Zhi Xianyu

Abstract Light fields with spatially varying backgrounds can modulate cosmic preheating, and imprint the nonlinear effects of preheating dynamics at tiny scales on large scale fluctuations. This provides us a unique probe into the preheating era which we dub the “cosmic microscope”. We identify a distinctive effect of preheating on scalar perturbations that turns the Gaussian primordial fluctuations of a light scalar field into square waves, like a diode. The effect manifests itself as local non-Gaussianity. We present a model, “modulated partial preheating”, where this nonlinear effect is consistent with current observations and can be reached by near future cosmic probes.


2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
D. Rodriguez-Gomez ◽  
J.G. Russo

Abstract We compute thermal 2-point correlation functions in the black brane AdS5 background dual to 4d CFT’s at finite temperature for operators of large scaling dimension. We find a formula that matches the expected structure of the OPE. It exhibits an exponentiation property, whose origin we explain. We also compute the first correction to the two-point function due to graviton emission, which encodes the proper time from the event horizon to the black hole singularity.


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