scholarly journals The Quantum Black Hole as a Gravitational Hydrogen Atom

2019 ◽  
Author(s):  
Christian Corda ◽  
Fabiano Feleppa
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Energy Spectrum ◽  
Hydrogen Atom ◽  
Gravitational Potential ◽  
Particle System ◽  
Energy Levels ◽  
Planck Scale ◽  
Dinger Equation ◽  
The One

In this paper only one basic assumption has been made: if we try to describe black holes, their behavior should be understood in the same language as the one we use for particles; black holes should be treated just like atoms. They must be quantum forms of matter, moving in accordance with Schrödinger equations just like everything else. In particular, Rosen’s quantization approach to the gravitational collapse is applied in the simple case of a pressureless “star of dust” by finding the gravitational potential, the Schrödinger equation and the solution for the collapse’s energy levels. By applying the constraints for a Schwarzschild black hole (BH) and by using the concept of BH effective state, previously introduced by one of the authors (CC), the BH quantum gravitational potential, Schrödinger equation and the BH energy spectrum are found. Remarkably, such an energy spectrum is in agreement (in its absolute value) with the one which was conjectured by Bekenstein in 1974 and consistent with other ones in the literature. This approach also permits to find an interesting quantum representation of the Schwarzschild BH ground state at the Planck scale. Moreover, two fundamental issues about black hole quantum physics are addressed by this model: the area quantization and the singularity resolution. As regards the former, a result similar to the one obtained by Bekenstein, but with a different coefficient, has been found. About the latter, it is shown that the traditional classical singularity in the core of the Schwarzschild BH is replaced, in a full quantum treatment, by a two-particle system where the two components strongly interact with each other via a quantum gravitational potential. The two-particle system seems to be non-singular from the quantum point of view and is analogous to the hydrogen atom because it consists of a “nucleus” and an “electron”.

scholarly journals Black Hole as Gravitational Hydrogen Atom by Rosen’s Quantization Approach

2018 ◽  
Author(s):  
Christian Corda ◽  
Fabiano Feleppa
Keyword(s):  
Black Hole ◽  
Mass Spectrum ◽  
Hydrogen Atom ◽  
Gravitational Collapse ◽  
Gravitational Potential ◽  
Ground State ◽  
Energy Levels ◽  
Planck Scale ◽  
Schroedinger Equation ◽  
Exact Quantum

We apply Rosen’s approach to the quantization of the gravitational collapse in the simple case of a pressureless “star of dust” and we find the gravitational potential, the Schroedinger equation and the solution for the collapse’s energy levels without any approximation. By applying the constrains for a black hole (BH), we found the analogous quantum quantities and the BH mass spectrum, again without any approximation. Remarkably, such a mass spectrum is the same which was found by Beken- stein in 1974. Finally, our approach permits to find the exact quantum representation of the Schwarzschild BH ground state at the Planck scale.

scholarly journals Black Hole as Gravitational Hydrogen Atom by Rosen’s Quantization Approach

2018 ◽  
Author(s):  
Christian Corda ◽  
Fabiano Feleppa
Keyword(s):  
Black Hole ◽  
Mass Spectrum ◽  
Hydrogen Atom ◽  
Gravitational Collapse ◽  
Gravitational Potential ◽  
Ground State ◽  
Energy Levels ◽  
Planck Scale ◽  
Schroedinger Equation ◽  
Exact Quantum

We apply Rosen’s approach to the quantization of the gravitational collapse in the simple case of a pressureless “star of dust” and we find the gravitational potential, the Schroedinger equation and the solution for the collapse’s energy levels without any approximation. By applying the constrains for a black hole (BH), we found the analogous quantum quantities and the BH mass spectrum, again without any approximation. Remarkably, such a mass spectrum is the same which was found by Beken- stein in 1974. Finally, our approach permits to find the exact quantum representation of the Schwarzschild BH ground state at the Planck scale.

Accretion onto a Black Hole

2014 ◽  
Author(s):  
Charles D. Bailyn
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Potential Energy ◽  
Gravitational Potential ◽  
Gas Flow ◽  
Gravitational Potential Energy ◽  
Spherically Symmetric ◽  
Potential Well ◽  
Accretion Flows ◽  
Flow Geometry

This chapter explores the ways that accretion onto a black hole produces energy and radiation. As material falls into a gravitational potential well, energy is transformed from gravitational potential energy into other forms of energy, so that total energy is conserved. Observing such accretion energy is one of the primary ways that astrophysicists pinpoint the locations of potential black holes. The spectrum and intensity of this radiation is governed by the geometry of the gas flow, the mass infall rate, and the mass of the accretor. The simplest flow geometry is that of a stationary object accreting mass equally from all directions. Such spherically symmetric accretion is referred to as Bondi-Hoyle accretion. However, accretion flows onto black holes are not thought to be spherically symmetric—the infall is much more frequently in the form of a flattened disk.

The entropy evolution of a Schwarzschild–(Anti) de Sitter black hole

2020 ◽  
Vol 29 (07) ◽  
pp. 2050048
Author(s):  
Xin-Yang Wang ◽  
Yi-Ru Wang ◽  
Wen-Biao Liu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Scalar Field ◽  
Hawking Radiation ◽  
Dynamical Variable ◽  
De Sitter ◽  
The One ◽  
Definition Of ◽  
Spherically Symmetry ◽  
Interior Volume

Based on the definition of the interior volume of spherically symmetry black holes, the interior volume of Schwarzschild–(Anti) de Sitter black holes is calculated. It is shown that with the cosmological constant ([Formula: see text]) increasing, the changing behaviors of both the position of the largest hypersurface and the interior volume for the Schwarzschild–Anti de Sitter black hole are the same as the Schwarzschild–de Sitter black hole. Considering a scalar field in the interior volume and Hawking radiation with only energy, the evolution relation between the scalar field entropy and Bekenstein–Hawking entropy is constructed. The results show that the scalar field entropy is approximately proportional to Bekenstein–Hawking entropy during Hawking radiation. Meanwhile, the proportionality coefficient is also regarded as a constant approximately with the increasing [Formula: see text]. Furthermore, considering [Formula: see text] as a dynamical variable, the modified Stefan–Boltzmann law is proposed which can be used to describe the variation of both the mass and [Formula: see text] under Hawking radiation. Using this modified law, the evolution relation between the two types of entropy is also constructed. The results show that the coefficient for Schwarzschild–de Sitter black holes is closer to a constant than the one for Schwarzschild–Anti de Sitter black holes during the evaporation process. Moreover, we find that for Hawking radiation carrying only energy, the evolution relation is a special case compared with the situation that the mass and [Formula: see text] are both considered as dynamical variables.

scholarly journals Energy spectrum of black holes: A new view

2016 ◽  
Vol 32 (02) ◽  
pp. 1750002 ◽  
Author(s):  
Abhishek Majhi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Energy Spectrum ◽  
Loop Quantum Gravity ◽  
Quantization Scheme ◽  
Geometric Description ◽  
Hole Energy ◽  
Energy Quantization ◽  
Asymptotic Energy ◽  
New View

Energy of a black hole is usually quantized by invoking some area quantization scheme after expressing the energy in terms of the horizon area. However, in this approach one has to quantize the local and asymptotic energy of the black hole separately and the two results do not manifest any physical correspondence with each other. Here, as opposed to this practice, we find the unique energy spectrum of black holes by adopting a top-down approach. The physical links among the underlying quantum theory, statistical mechanics and thermodynamics of the black hole horizon play the central role in determining the energy spectrum. The energy spectrum that we obtain explicitly reveals the correspondence between asymptotic and local observations through the presence of the surface gravity of the horizon as a parameter in the spectrum, rather than being expressed as a function of area and consequently getting quantized in the usual approach. Thus, our result presents a new view as far as black hole energy quantization is concerned. The calculations are performed using the quantum geometric description of black hole horizons as laid down by loop quantum gravity.

scholarly journals EHT Constraint on the Ultralight Scalar Hair of the M87 Supermassive Black Hole

Universe ◽  
2019 ◽  
Vol 5 (12) ◽  
pp. 220 ◽  
Author(s):  
Pedro Cunha ◽  
Carlos Herdeiro ◽  
Eugen Radu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Bosonic Field ◽  
Massive Black Holes ◽  
Scalar Particles ◽  
Supermassive Black Hole ◽  
Valued Field ◽  
Hairy Black Holes ◽  
The One ◽  
Complex Valued

Hypothetical ultralight bosonic fields will spontaneously form macroscopic bosonic halos around Kerr black holes, via superradiance, transferring part of the mass and angular momentum of the black hole into the halo. Such a process, however, is only efficient if resonant—when the Compton wavelength of the field approximately matches the gravitational scale of the black hole. For a complex-valued field, the process can form a stationary, bosonic field black hole equilibrium state—a black hole with synchronised hair. For sufficiently massive black holes, such as the one at the centre of the M87 supergiant elliptic galaxy, the hairy black hole can be robust against its own superradiant instabilities, within a Hubble time. Studying the shadows of such scalar hairy black holes, we constrain the amount of hair which is compatible with the Event Horizon Telescope (EHT) observations of the M87 supermassive black hole, assuming the hair is a condensate of ultralight scalar particles of mass μ ∼ 10 − 20 eV, as to be dynamically viable. We show the EHT observations set a weak constraint, in the sense that typical hairy black holes that could develop their hair dynamically, are compatible with the observations, when taking into account the EHT error bars and the black hole mass/distance uncertainty.

scholarly journals QUANTIZATION OF BLACK HOLES ENTROPY AND ITS COSMOLOGICAL CONSEQUENCES

2013 ◽  
Vol 28 (16) ◽  
pp. 1350066 ◽  
Author(s):  
G. CRISTOFANO ◽  
G. MAIELLA ◽  
C. STORNAIOLO
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Degrees Of Freedom ◽  
Energy Levels ◽  
Hawking Temperature ◽  
Simple Interpretation ◽  
Level Number ◽  
Black Hole Temperature ◽  
Extremal Black Holes

Starting from a quantization relation for primordial extremal black holes with electric and magnetic charges, it is shown that their entropy is quantized. Furthermore, the energy levels spacing for such black holes is derived as a function of the level number n, appearing in the quantization relation. Some interesting cosmological consequences are presented for small values of n. By producing a mismatch between the mass and the charge, the black hole temperature is derived and its behavior investigated. Finally extending the quantum relation to Schwarzschild black holes their temperature is found to be in agreement with the Hawking temperature and a simple interpretation of the microscopic degrees of freedom of the black holes is given.

Thermal relativity, modified Hawking radiation, and the generalized uncertainty principle

2019 ◽  
Vol 16 (10) ◽  
pp. 1950156
Author(s):  
Carlos Castro Perelman
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hawking Radiation ◽  
Uncertainty Relation ◽  
Generalized Uncertainty Principle ◽  
Black Hole Entropy ◽  
The Novel ◽  
Black Hole Information ◽  
The One ◽  
Mini Black Holes

After a brief review of the thermal relativistic corrections to the Schwarzschild black hole entropy, it is shown how the Stefan–Boltzman law furnishes large modifications to the evaporation times of Planck-size mini-black holes, and which might furnish important clues to the nature of dark matter and dark energy since one of the novel consequences of thermal relativity is that black holes do not completely evaporate but leave a Planck size remnant. Equating the expression for the modified entropy (due to thermal relativity corrections) with Wald’s entropy should, in principle, determine the functional form of the modified gravitational Lagrangian [Formula: see text]. We proceed to derive the generalized uncertainty relation which corresponds to the effective temperature [Formula: see text] associated with thermal relativity and given in terms of the Hawking ([Formula: see text]) and Planck ([Formula: see text]) temperature, respectively. Such modified uncertainty relation agrees with the one provided by string theory up to first order in the expansion in powers of [Formula: see text]. Both lead to a minimal length (Planck size) uncertainty. Finally, an explicit analytical expression is found for the modifications to the purely thermal spectrum of Hawking radiation which could cast some light into the resolution of the black hole information paradox.

Lower-dimensional corpuscular gravity and the end of black hole evaporation

2019 ◽  
Vol 34 (22) ◽  
pp. 1950174
Author(s):  
Roberto Casadio ◽  
Andrea Giusti ◽  
Jonas Mureika
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Occupation Number ◽  
Planck Scale ◽  
Friedmann Equation ◽  
Dimensional Spacetime ◽  
Spatial Dimensions ◽  
Bose Einstein ◽  
Lower Dimensional ◽  
Hawking Evaporation

Black holes in [Formula: see text] spatial dimensions are studied from the perspective of the corpuscular model of gravitation, in which black holes are described as Bose–Einstein condensates (BEC) of (virtual soft) gravitons. In particular, since the energy of these gravitons should increase as the black hole evaporates, eventually approaching the Planck scale, the lower-dimensional cases could provide important insight into the late stages and end of Hawking evaporation. We show that the occupation number of gravitons in the condensate scales holographically in all dimensions as [Formula: see text], where [Formula: see text] is the relevant length for the system in the [Formula: see text]-dimensional spacetime. In particular, this analysis shows that black holes cannot contain more than a few gravitons in [Formula: see text]. Since dimensional reduction is a common feature of many models of quantum gravity, this result can shed light on the end of the Hawking evaporation. We also consider [Formula: see text]-dimensional cosmology in the context of corpuscular gravity and show that the Friedmann equation reproduces the expected holographic scaling as in higher dimensions.

scholarly journals WHAT DID WE LEARN FROM STUDYING ACOUSTIC BLACK HOLES?

2002 ◽  
Vol 17 (20) ◽  
pp. 2721-2725 ◽  
Author(s):  
RENAUD PARENTANI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hawking Radiation ◽  
Asymptotic Properties ◽  
Planck Scale ◽  
Density Fluctuations ◽  
Effective Theory ◽  
Linear Dispersion ◽  
Black Hole Evaporation ◽  
Acoustic Black Holes

The study of acoustic black holes has been undertaken to provide new insights about the role of high frequencies in black hole evaporation. Because of the infinite gravitational redshift from the event horizon, Hawking quanta emerge from configurations which possessed ultra high (trans-Planckian) frequencies. Therefore Hawking radiation cannot be derived within the framework of a low energy effective theory; and in all derivations there are some assumptions concerning Planck scale physics. The analogy with condensed matter physics was thus introduced to see if the asymptotic properties of the Hawking phonons emitted by an acoustic black hole, namely stationarity and thermality, are sensitive to the high frequency physics which stems from the granular character of matter and which is governed by a non-linear dispersion relation. In 1995 Unruh showed that they are not sensitive in this respect, in spite of the fact that phonon propagation near the (acoustic) horizon drastically differs from that of photons. In 2000 the same analogy was used to establish the robustness of the spectrum of primordial density fluctuations in inflationary models. This analogy is currently stimulating research for experimenting Hawking radiation. Finally it could also be a useful guide for going beyond the semi-classical description of black hole evaporation.

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