scholarly journals Schwarzschild black hole and generalized second law in phantom-dominated universe

2007 ◽  
Vol 645 (2-3) ◽  
pp. 108-112 ◽  
Author(s):  
H. Mohseni Sadjadi
Keyword(s):  
Black Hole ◽  
Second Law ◽  
Schwarzschild Black Hole ◽  
Generalized Second Law

scholarly journals THERMODYNAMICS OF A SCHWARZSCHILD BLACK HOLE IN PHANTOM COSMOLOGY WITH ENTROPY CORRECTIONS

2012 ◽  
Vol 21 (07) ◽  
pp. 1250065 ◽  
Author(s):  
MUBASHER JAMIL ◽  
D. MOMENI ◽  
KAZUHARU BAMBA ◽  
RATBAY MYRZAKULOV
Keyword(s):  
Black Hole ◽  
Power Law ◽  
Phantom Energy ◽  
Upper Bounds ◽  
Quantum Corrections ◽  
Second Law ◽  
Schwarzschild Black Hole ◽  
Frw Universe ◽  
Generalized Second Law ◽  
Entropy Corrections

Motivated by some earlier works [G. Izquierdo and D. Pavon, Phys. Lett. B 639 (2006) 1; H. M. Sadjadi, Phys. Lett. B 645 (2007) 108.] dealing with the study of generalized second law (GSL) of thermodynamics for a system comprising of a Schwarzschild black hole accreting a test nonself-gravitating fluid namely phantom energy in FRW universe, we extend them when the entropy of horizons of black hole and the cosmological undergo quantum corrections. Two types of such corrections are relevant here including logarithmic and power-law, while both are motivated from different theoretical backgrounds. We obtain general mathematical conditions for the validity of GSL in each case. Further we find that GSL restricts the mass of black hole for accretion of phantom energy. As such we obtain upper bounds on the mass of black hole above which the black hole cannot accrete the phantom fluid, otherwise the GSL is violated.

scholarly journals Particle absorption by black holes and the generalized second law of thermodynamics

2009 ◽  
Vol 466 (2116) ◽  
pp. 1155-1166 ◽  
Author(s):  
Scott Funkhouser
Keyword(s):  
Black Hole ◽  
Cross Section ◽  
Probability Function ◽  
Second Law Of Thermodynamics ◽  
Quantum Mechanical ◽  
Statistical Interpretation ◽  
Schwarzschild Black Hole ◽  
Particle Absorption ◽  
Generalized Second Law ◽  
Fundamental Physical

The change in entropy, Δ S , associated with the quasi-static absorption of a particle of energy ε by a Schwarzschild black hole (ScBH) is approximately ( ε / T )− s , where T is the Hawking temperature of the black hole and s is the entropy of the particle. Motivated by the statistical interpretation of entropy, it is proposed here that the absorption should be suppressed, but not forbidden, when Δ S <0, which requires the absorption cross section to be sensitive to Δ S . A purely thermodynamic formulation of the probability for the absorption is obtained from the standard relationship between microstates and entropy. If Δ S ≫1 and s ≪ ε / T , then the probability for the particle not to be absorbed is approximately exp[− ε / T ], which is identical to the probability for quantum mechanical reflection by the horizon of an ScBH. The manifestation of quantum behaviours in the new probability function may intimate a fundamental physical unity between thermodynamics and quantum mechanics.

scholarly journals ENTROPY OF COSMOLOGICAL BLACK HOLES AND THE GENERALIZED SECOND LAW IN THE PHANTOM-ENERGY-DOMINATED UNIVERSE

2011 ◽  
Vol 20 (02) ◽  
pp. 233-252 ◽  
Author(s):  
KHIREDDINE NOUICER
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Equation Of State ◽  
State Parameter ◽  
Phantom Energy ◽  
Energy Conditions ◽  
Second Law ◽  
Brick Wall ◽  
Generalized Second Law ◽  
Equation Of State Parameter

Adopting the thin layer improved brick wall method, we investigate the thermodynamics of a black hole embedded in a spatially flat Friedmann–Robertson–Walker universe. We calculate the temperature and the entropy at every apparent horizon for arbitrary solution of the scale factor. We show that the temperature and entropy display a nontrivial behavior as functions of time. In the case of black holes immersed in a universe driven by phantom energy, we show that for specific ranges of the equation-of-state parameter and apparent horizons the entropy is compatible with the D-bound conjecture, and even the null, dominant and strong energy conditions are violated. In the case of accretion of phantom energy onto a black hole with small Hawking–Hayward quasi-local mass, we obtain an equation-of-state parameter in the range w ≤ -5/3, guaranteeing the validity of the generalized second law.

scholarly journals Hawking radiation from universal horizons

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Mario Herrero-Valea ◽  
Stefano Liberati ◽  
Raquel Santos-Garcia
Keyword(s):  
Black Hole ◽  
Hawking Radiation ◽  
Black Hole Thermodynamics ◽  
Second Law ◽  
Consistency Test ◽  
First Law Of Thermodynamics ◽  
Generalized Second Law ◽  
Theories Of Gravity ◽  
Per Se ◽  
Suitable Notion

Abstract The persistence of a suitable notion of black hole thermodynamics in Lorentz breaking theories of gravity is not only a non-trivial consistency test for such theories, it is also an interesting investigation per se, as it might help us identifying the crucial features at the root of these surprising laws governing such purely gravitational objects. In past investigations, controversial findings were presented in this sense. With the aim of settling this issue, we present here two complementary derivations of Hawking radiation in geometries endowed with universal horizons: a novel feature of back holes in Lorentz breaking theories of gravity which reproduces several properties normally characterizing Killing horizons. We find that both the derivations agree on the fact that the Hawking temperature associated to these geometries is set by the generalized universal horizon peeling surface gravity, as required for consistency with extant derivations of the first law of thermodynamics for these black holes. We shall also comment on the compatibility of our results with previous alternative derivations and on their significance for the survival of the generalized second law of black hole thermodynamics in Lorentz breaking theories of gravity.

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