EINSTEIN–PLANCK FORMULA, EQUIVALENCE PRINCIPLE, AND BLACK HOLE RADIANCE

The presence of gravity implies corrections to the Einstein–Planck formula E = hν. This gives hope that the divergent blueshift in frequency, associated to the presence of a black hole horizon, could be smoothed out for the energy. Using simple arguments based on Einstein's equivalence principle, we show that this is only possible if a black hole emits, in a first approximation, not just a single particle, but thermal radiation.

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The fate of Schwarzschild–de Sitter black holes in f(R) gravity

Modern Physics Letters A ◽

10.1142/s0217732316500541 ◽

2016 ◽

Vol 31 (09) ◽

pp. 1650054 ◽

Cited By ~ 19

Author(s):

Andrea Addazi ◽

Salvatore Capozziello

Keyword(s):

Black Holes ◽

Black Hole ◽

Thermal Radiation ◽

Black Hole Physics ◽

Black Hole Horizon ◽

De Sitter ◽

Trapped Surfaces ◽

Emission Time ◽

Marginally Trapped Surfaces

The semiclassical effects of anti-evaporating black holes can be discussed in the framework of f(R) gravity. In particular, the Bousso–Hawking–Nojiri–Odinstov anti-evaporation instability of degenerate Schwarzschild–de Sitter black holes (the so-called Nariai spacetime) leads to a dynamical increasing of black hole horizon in f(R) gravity. This phenomenon causes the following transition: emitting marginally trapped surfaces (TS) become space-like surfaces before the effective Bekenstein–Hawking emission time. As a consequence, Bousso–Hawking thermal radiation cannot be emitted in an anti-evaporating Nariai black hole. Possible implications in cosmology and black hole physics are also discussed.

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Long-Range Quantum Gravity

Symmetry ◽

10.3390/sym12091396 ◽

2020 ◽

Vol 12 (9) ◽

pp. 1396

Author(s):

Mariano Cadoni ◽

Matteo Tuveri ◽

Andrea P. Sanna

Keyword(s):

Black Holes ◽

General Relativity ◽

Black Hole ◽

Quantum Gravity ◽

Long Range ◽

Equivalence Principle ◽

Quantum Criticality ◽

Black Hole Thermodynamics ◽

Gravitational Effects ◽

Einstein's Equivalence Principle

It is a tantalising possibility that quantum gravity (QG) states remaining coherent at astrophysical, galactic and cosmological scales could exist and that they could play a crucial role in understanding macroscopic gravitational effects. We explore, using only general principles of General Relativity, quantum and statistical mechanics, the possibility of using long-range QG states to describe black holes. In particular, we discuss in a critical way the interplay between various aspects of long-range quantum gravity, such as the holographic bound, classical and quantum criticality and the recently proposed quantum thermal generalisation of Einstein’s equivalence principle. We also show how black hole thermodynamics can be easily explained in this framework.

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