scholarly journals Distinguishing black holes through their ringing

SURG Journal ◽  
2010 ◽  
Vol 4 (1) ◽  
pp. 87-92
Author(s):  
Shannon Potter ◽  
Luis Lehner
Keyword(s):  
Black Hole ◽  
Gravitational Wave ◽  
Black Hole Solution ◽  
Alternative Explanation ◽  
Quasinormal Modes ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Schwarzschild Black Hole ◽  
Black Hole Spacetime ◽  
Hole Model

A perturbed black hole spacetime emits gravitational waves possessing quasinormal modes that are characteristic of the black hole itself. We use a massless scalar field as an analog to a gravitational wave to find the quasinormal modes emitted by both a Schwarzschild black hole and a new alternative black hole model which places the Schwarzschild black hole in an aether—a zero density, negative pressure perfect fluid. The later model was proposed as an alternative explanation for accelerated cosmic expansion [1]. We construct a computational code to study both systems numerically and obtain the corresponding quasinormal modes. We find that the quasinormal modes of a black hole in an aether are distinguishable from those of a Schwarzschild black hole and so, in principle, gravitational wave observations could be exploited to determine if either black hole solution represents those existing in our universe.

scholarly journals Massive scalar field quasinormal modes of a Schwarzschild black hole surrounded by quintessence

Open Physics ◽  
2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Chunrui Ma ◽  
Yuanxing Gui ◽  
Wei Wang ◽  
Fujun Wang
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Quasinormal Modes ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Massive Scalar ◽  
Schwarzschild Black Hole ◽  
Third Order ◽  
Massive Scalar Field ◽  
Absolute Value

AbstractWe present the quasinormal frequencies of the massive scalar field in the background of a Schwarzchild black hole surrounded by quintessence with the third-order WKB method. The mass of the scalar field u plays an important role in studying the quasinormal frequencies, the real part of the frequencies increases linearly as mass of the field u increases, while the imaginary part in absolute value decreases linearly which leads to damping more slowly than the massless scalar field. The frequencies have a limited value, so it is easier to detect the quasinormal modes. Moreover, owing to the presence of the quintessence, the massive scalar field damps more slowly.

scholarly journals High-dimensional Schwarzschild black holes in scalar–tensor–vector gravity theory

2021 ◽  
Vol 81 (6) ◽  
Author(s):  
Xin-Chang Cai ◽  
Yan-Gang Miao
Keyword(s):  
Black Hole ◽  
Black Hole Solution ◽  
Emission Rate ◽  
Null Geodesic ◽  
High Dimensional ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Spacetime Dimension ◽  
Schwarzschild Black Hole ◽  
Scalar Waves

AbstractWe obtain a high-dimensional Schwarzschild black hole solution in the scalar–tensor–vector gravity (STVG), and then analyze the influence of parameter $$\alpha $$ α associated with a deviation of the STVG theory from General Relativity on event horizons and Hawking temperature. We calculate the quasinormal mode frequencies of massless scalar field perturbations for the high-dimensional Schwarzschild STVG black hole by using the sixth-order WKB approximation method and the unstable null geodesic method in the eikonal limit. The results show that the increase of parameter $$\alpha $$ α makes the scalar waves decay slowly, while the increase of the spacetime dimension makes the scalar waves decay fast. In addition, we study the influence of parameter $$\alpha $$ α on the shadow radius of this high-dimensional Schwarzschild STVG black hole and find that the increase of parameter $$\alpha $$ α makes the black hole shadow radius increase, but the increase of the spacetime dimension makes the black hole shadow radius decrease. Finally, we investigate the energy emission rate of the high-dimensional Schwarzschild STVG black hole, and find that the increase of parameter $$\alpha $$ α makes the evaporation process slow, while the increase of the spacetime dimension makes the process fast.

scholarly journals Harvesting correlations in Schwarzschild and collapsing shell spacetimes

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Erickson Tjoa ◽  
Robert B. Mann
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Proper Time ◽  
Time Derivative ◽  
Vacuum State ◽  
Massless Scalar ◽  
Late Time ◽  
Massless Scalar Field ◽  
Schwarzschild Black Hole ◽  
Black Hole Spacetime

Abstract We study the harvesting of correlations by two Unruh-DeWitt static detectors from the vacuum state of a massless scalar field in a background Vaidya spacetime consisting of a collapsing null shell that forms a Schwarzschild black hole (hereafter Vaidya spacetime for brevity), and we compare the results with those associated with the three preferred vacua (Boulware, Unruh, Hartle-Hawking-Israel vacua) of the eternal Schwarzschild black hole spacetime. To do this we make use of the explicit Wightman functions for a massless scalar field available in (1+1)-dimensional models of the collapsing spacetime and Schwarzschild spacetimes, and the detectors couple to the proper time derivative of the field. First we find that, with respect to the harvesting protocol, the Unruh vacuum agrees very well with the Vaidya vacuum near the horizon even for finite-time interactions. Second, all four vacua have different capacities for creating correlations between the detectors, with the Vaidya vacuum interpolating between the Unruh vacuum near the horizon and the Boulware vacuum far from the horizon. Third, we show that the black hole horizon inhibits any correlations, not just entanglement. Finally, we show that the efficiency of the harvesting protocol depend strongly on the signalling ability of the detectors, which is highly non-trivial in presence of curvature. We provide an asymptotic analysis of the Vaidya vacuum to clarify the relationship between the Boulware/Unruh interpolation and the near/far from horizon and early/late-time limits. We demonstrate a straightforward implementation of numerical contour integration to perform all the calculations.

Joule–Thomson expansion and quasinormal modes of regular non-minimal magnetic black hole

2020 ◽  
Vol 35 (36) ◽  
pp. 2050298
Author(s):  
Abdul Jawad ◽  
Muhammad Yasir ◽  
Shamaila Rani
Keyword(s):  
Black Hole ◽  
Mass Formula ◽  
Quasinormal Modes ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Thomson Effect ◽  
First Order ◽  
Thermodynamical Parameters ◽  
Klein Gordon ◽  
Tortoise Coordinate

The Joule–Thomson effect and quasinormal modes (QNM) onto regular non-minimal magnetic charged black hole with a cosmological constant are being investigated. For this purpose, we extract some thermodynamical parameters such as pressure [Formula: see text] and mass [Formula: see text] in the presence of magnetic [Formula: see text] as well as electric [Formula: see text] charge. These parameters lead to inversion temperature [Formula: see text], pressure [Formula: see text] and corresponding isenthalpic curves. We introduce the tortoise coordinate and the Klein–Gordon wave equation which leads to the second-order ordinary Schrödinger equation. We find out the complex frequencies of QNMs through the massless scalar field perturbation which satisfy boundary conditions by using the first-order Wentzel–Kramers–Brillouin (WKB) technique.

scholarly journals The correspondence between shadow and test field in a four-dimensional charged Einstein–Gauss–Bonnet black hole

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Deyou Chen ◽  
Chuanhong Gao ◽  
Xianming Liu ◽  
Chengye Yu
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Quasinormal Modes ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Test Field ◽  
Coupling Constant ◽  
Approximation Approach ◽  
The Real ◽  
Constant Increase

AbstractIn this paper, we investigate the photon sphere, shadow radius and quasinormal modes of a four-dimensional charged Einstein–Gauss–Bonnet black hole. The perturbation of a massless scalar field in the black hole’s background is adopted. The quasinormal modes are gotten by the 6th order WKB approximation approach and shadow radius, respectively. When the value of the Gauss–Bonnet coupling constant increase, the values of the real parts of the quasinormal modes increase and those of the imaginary parts decrease. The coincidence degrees of quasinormal modes derived by the two approaches increases with the increase of the values of the Gauss–Bonnet coupling constant and multipole number. It shows the correspondence between the shadow and test field in the four-dimensional Einstein–Gauss–Bonnet–Maxwell gravity. The radii of the photon sphere and shadow increase with the decrease of the Gauss–Bonnet coupling constant.

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