scholarly journals Quantum gravity corrections to accretion onto a Schwarzschild black hole

2015 ◽  
Vol 92 (8) ◽  
Author(s):  
Rongjia Yang
2020 ◽  
Vol 35 (11) ◽  
pp. 2050081
Author(s):  
Baljeet Kaur Lotte ◽  
Subodha Mishra

The expressions for the corrected radius and the Hawking temperature of a Schwarzschild black hole are derived by calculating the total energy of a self-gravitating system of N fermions when the corrections to gravitational interaction due to post-Newtonian-like self-energy due to two graviton exchange- and one-loop contribution of quantum gravity effect are included. Since the particles are fermions, the exchange-correlation energy is also included consistently. It is found that though the three corrections are small, the correction due to the exchange-correlation is much more than the other two. The configuration of the many-particle system that we study is possible since it has no Buchdahl limit in the post-Newtonian approximation.


2021 ◽  
Vol 81 (9) ◽  
Author(s):  
Fabián H. Zuluaga ◽  
Luis A. Sánchez

AbstractWe study quantum gravity effects on radiation properties of thin accretion disks around a renormalization group improved (RGI-) Schwarzschild black hole. In the infrared (IR) limit of the asymptotically safe theory with higher derivatives, the running Newton coupling G(r) depends on a free parameter which encodes the quantum effects on the spacetime geometry. By varying this parameter, modifications to thermal properties of the disk as the time averaged energy flux, the disk temperature, the differential luminosity, and the conversion efficiency of accreting mass into radiation, are obtained. In addition to a shifting of the radius of the innermost stable circular orbit (ISCO) toward small values, we find an increase of the maximum values of these thermal properties and a greater efficiency than in the classical relativistic regime. We discuss astrophysical applications of these results by using observational data of the stellar-mass black hole candidate LMC X-3. Our findings could, in principle, be used to identify quantum gravity effects through astrophysical observations.


2020 ◽  
Vol 80 (12) ◽  
Author(s):  
J. A. Rosabal

AbstractIn this work, we define a quantum gravity state on a nice slice. The nice slices provide a foliation of spacetime and avoid regions of strong curvature. We explore the topology and the geometry of the manifold obtained from a nice slice after evolving it in complex time. We compute its associated semiclassical thermodynamics entropy for a 4d Schwarzschild black hole. Despite the state one can define on a nice slice is not a global pure state, remarkably, we get a similar result to Hawking’s calculation. In the end, we discuss the entanglement entropy of two segments on a nice slice and comment on the relation of this work with the replica wormhole calculation.


2020 ◽  
Vol 2020 (07) ◽  
pp. 066-066 ◽  
Author(s):  
Mariam Bouhmadi-López ◽  
Suddhasattwa Brahma ◽  
Che-Yu Chen ◽  
Pisin Chen ◽  
Dong-han Yeom

2019 ◽  
Vol 97 (5) ◽  
pp. 562-565
Author(s):  
Cuibai Luo ◽  
Chen Wu

Noncommutative geometry may be an alternative way to quantum gravity. We study the influence of the space–time noncommutative parameter on the Dirac quasi-normal modes in the noncommutative Schwarzschild black hole space–times. In comparison to the commutative Schwarzschild black hole, the numerical results show that the oscillation frequencies and magnitude of the imaginary part of the Dirac quasi-normal modes will increase. However, it is found that the influence of the space–time noncommutative parameter on the Dirac quasi-normal modes is tiny and negligible.


Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan

This chapter discusses the Schwarzschild black hole. It demonstrates how, by a judicious change of coordinates, it is possible to eliminate the singularity of the Schwarzschild metric and reveal a spacetime that is much larger, like that of a black hole. At the end of its thermonuclear evolution, a star collapses and, if it is sufficiently massive, does not become stabilized in a new equilibrium configuration. The Schwarzschild geometry must therefore represent the gravitational field of such an object up to r = 0. This being said, the Schwarzschild metric in its original form is singular, not only at r = 0 where the curvature diverges, but also at r = 2m, a surface which is crossed by geodesics.


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