Quantum gravitational collapse of a scalar field and the wave function of black hole decay

1995 ◽  
Vol 52 (8) ◽  
pp. 4540-4547 ◽  
Author(s):  
Akira Tomimatsu
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.


2007 ◽  
Vol 22 (01) ◽  
pp. 65-74 ◽  
Author(s):  
RITUPARNO GOSWAMI ◽  
PANKAJ S. JOSHI

We construct and study here a class of collapsing scalar field models with a nonzero potential. The weak energy condition is satisfied by the collapsing configuration and it is shown that the end state of collapse could be either a black hole or a naked singularity. It is seen that physically it is the rate of collapse that governs these outcomes of the dynamical evolution. The implications for the cosmic censorship conjecture are discussed.


2014 ◽  
Vol 29 (35) ◽  
pp. 1450192 ◽  
Author(s):  
Muhammad Sharif ◽  
Rubab Manzoor

This paper investigates the phenomenon of gravitational collapse of Lemaitre–Tolman–Bondi (LTB) model in the presence of Brans–Dicke (BD) scalar field with nonzero potential field. We find a class of solutions by taking perfect fluid as well as scalar field and check the validity of weak energy conditions. It turns out that two different types of singularities are formed in the presence of scalar field. We conclude that the end state of gravitational collapse turns out to be a black hole (BH) contrary to general relativity (GR).


2014 ◽  
Vol 29 (02) ◽  
pp. 1450005 ◽  
Author(s):  
SANEESH SEBASTIAN ◽  
V. C. KURIAKOSE

In this work we have studied the scattering of scalar field around an extended black hole in F(R) gravity using WKB method. We have obtained the wave function in different regions such as near the horizon region, away from horizon and far away from horizon and the absorption cross-section are calculated. We find that the absorption cross-section is inversely proportional to the cube of Hawking temperature. We have also evaluated the Hawking temperature of the black hole via tunneling method.


1997 ◽  
Vol 12 (20) ◽  
pp. 1491-1505 ◽  
Author(s):  
P. V. Moniz

We study the quantum behavior of Reissner–Nordström (RN) black holes interacting with a complex scalar field. A Maxwell field is also present. Our analysis is based on M. Pollock's1 method and is characterized by solving a Wheeler–DeWitt equation in the proximity of an apparent horizon of the RN space–time. Subsequently, we obtain a wave function Ψ RN [M,Q] representing the RN black hole when its charge, |Q|, is small in comparison with its mass, M. We then compare quantum-mechanically the cases of (i) Q=0 and (ii) M≥|Q|≠0. A special emphasis is given to the evolution of the mass-charge rate affected by Hawking radiation.


2017 ◽  
Vol 26 (04) ◽  
pp. 1750028 ◽  
Author(s):  
Eric Greenwood

We investigate both the classical and quantum gravitational collapse of a massive, charged, nonrotating [Formula: see text]-dimensional Bañados–Teitelboim–Zanelli (BTZ)-like domain wall in AdS space. In the classical picture, we show that, as far as the asymptotic observer is concerned, the details of the collapse depend on the amount of charge present in the domain wall; that is, if the domain wall is extremal, nonextremal or overcharged. In both the extremal and nonextremal cases, the collapse takes an infinite amount of observer time to complete. However, in the over-charged case, the collapse never actually occurs, instead one finds an oscillatory solution which prevents the formation of a naked singularity. As far as the infalling observer is concerned, in the nonextremal case, the collapse is completed within a finite amount of proper time. Thus, the gravitational collapse follows that of the typical formation of a black hole via gravitational collapse.Quantum mechanically, we take the absence of induced quasi-particle production and fluctuations of the metric geometry; that is, we ignore the effect of radiation and back-reaction. For the asymptotic observer, we find that, near the horizon, quantization of the domain wall does not allow the formation of the black hole in a finite amount of observer time. For the infalling observer, we are primarily interested in the quantum mechanical effect as the domain wall approaches the classical singularity. In this region, the main result is that the wave function exhibits nonlocal effects, demonstrated by the fact that the Hamiltonian depends on an infinite number of derivatives that cannot be truncated after a finite number of terms. Furthermore, in the large energy density limit, the wave function vanishes at the classical singularity implying that quantization does not rid the black hole of its singularity.


2018 ◽  
Vol 27 (11) ◽  
pp. 1843009 ◽  
Author(s):  
Carlos A. R. Herdeiro ◽  
Eugen Radu

We obtain spinning boson star solutions and hairy black holes with synchronized hair in the Einstein–Klein–Gordon model, wherein the scalar field is massive, complex and with a nonminimal coupling to the Ricci scalar. The existence of these hairy black holes in this model provides yet another manifestation of the universality of the synchronization mechanism to endow spinning black holes with hair. We study the variation of the physical properties of the boson stars and hairy black holes with the coupling parameter between the scalar field and the curvature, showing that they are, qualitatively, identical to those in the minimally coupled case. By discussing the conformal transformation to the Einstein frame, we argue that the solutions herein provide new rotating boson star and hairy black hole solutions in the minimally coupled theory, with a particular potential, and that no spherically symmetric hairy black hole solutions exist in the nonminimally coupled theory, under a condition of conformal regularity.


2012 ◽  
Vol 21 (11) ◽  
pp. 1242010
Author(s):  
ARIEL EDERY ◽  
HUGUES BEAUCHESNE

Recent numerical simulations of gravitational collapse show that there exists a special foliation of the spacetime where matter and entropy accumulate directly on the inside of the horizon surface. In this foliation, the time coincides with the proper time of the asymptotic static observer (ASO) and for spherical symmetry, this corresponds to isotropic co-ordinates. In this gauge, the three-volume in the interior shrinks to zero and only the horizon area remains at the end of collapse. In a different foliation, matter and entropy accumulate in the volume. The entropy is however independent of the foliation. Black hole holography is therefore a mapping from an arbitrary foliation, where information resides in the volume, to the special ASO frame, where it resides directly on the horizon surface.


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