scholarly journals Extremal bifurcations of rotating AdS4 black holes

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Brett McInnes
Keyword(s):  
Black Holes ◽  
Magnetic Charge ◽  
Second Law Of Thermodynamics ◽  
Basic Question ◽  
Quantum Mechanical ◽  
Second Law ◽  
Rapid Rotation ◽  
Spinning Particles ◽  
Weak Gravity ◽  
Extremal Black Holes

Abstract The Weak Gravity Conjecture arises from the assertion that all extremal black holes, even those which are “classical” in the sense of being very massive, must decay by quantum-mechanical emission of particles or smaller black holes. This is interesting, because some observed astrophysical black holes are on the brink of being extremal — though this is due to rapid rotation rather than a large electric or magnetic charge. The possibility that rotating near-extremal black holes might, in addition to radiating spinning particles, also bifurcate by emitting smaller black holes, has attracted much attention of late. There is, however, a basic question to be answered here: can such a bifurcation be compatible with the second law of thermodynamics? This is by no means clear. Here we show that, if there is indeed such a mechanism for bifurcations of AdS4-Kerr-Newman black holes, then this process can in fact satisfy the second law.

scholarly journals Weak Gravity Conjecture and extremal black holes

2019 ◽  
Vol 62 (11) ◽  
Author(s):  
William Cottrell ◽  
Gary Shiu ◽  
Pablo Soler
Keyword(s):  
Black Holes ◽  
Weak Gravity ◽  
Extremal Black Holes

scholarly journals Phantom accretion by black holes and the generalized second law of thermodynamics

2010 ◽  
Vol 33 (5-6) ◽  
pp. 292-295 ◽  
Author(s):  
J.A.S. Lima ◽  
S.H. Pereira ◽  
J.E. Horvath ◽  
Daniel C. Guariento
Keyword(s):  
Black Holes ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Generalized Second Law

scholarly journals Probability, preclusion and biological evolution in Heisenberg-picture Everett quantum mechanics

2021 ◽  
pp. 2150117
Author(s):  
Mark A. Rubin
Keyword(s):  
Quantum Mechanics ◽  
State Vector ◽  
Biological Evolution ◽  
Second Law Of Thermodynamics ◽  
Quantum Mechanical ◽  
Second Law ◽  
Subjective Experiences ◽  
Everett Interpretation ◽  
Heisenberg Picture ◽  
Physical Laws

The fact that certain “extraordinary” probabilistic phenomena — in particular, macroscopic violations of the second law of thermodynamics — have never been observed to occur can be accounted for by taking hard preclusion as a basic physical law, i.e. precluding from existence events corresponding to very small but nonzero values of quantum-mechanical weight. This approach is not consistent with the usual ontology of the Everett interpretation, in which outcomes correspond to branches of the state vector, but can be successfully implemented using a Heisenberg-picture-based ontology in which outcomes are encoded in transformations of operators. Hard preclusion can provide an explanation for biological evolution, which can in turn explain our subjective experiences of, and reactions to, “ordinary” probabilistic phenomena, and the compatibility of those experiences and reactions with what we conventionally take to be objective probabilities arising from physical laws.

Thermodynamics, Quantum Physics, and Black Holes

2020 ◽  
pp. 24-39
Author(s):  
John W. Moffat
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Mechanics ◽  
Quantum Physics ◽  
Second Law Of Thermodynamics ◽  
Information Loss ◽  
Second Law ◽  
Major Question ◽  
Long Time ◽  
Information Loss Problem

A major question confronting physicists studying black holes was whether thermodynamics applied to them—that is, whether the black holes radiated heat and lost energy. Bekenstein considered heat and thermodynamics important for the interior of black holes. Based on the second law of thermodynamics, Hawking proposed that black holes evaporate over a very long time through what we now call Hawking radiation. This concept contradicts the notion that nothing can escape a black hole event horizon. Quantum physics enters into Hawking’s calculations, and he discovered the conundrum that the radiation would violate quantum mechanics, leading to what is called the information loss problem. These ideas are still controversial, and many physicists have attempted to resolve them, including Russian theorists Zel’dovich and Starobinsky. Alternative quantum physics interpretations of black holes have been proposed that address the thermodynamics problems, including so-called gravastars.

scholarly journals Maxwell’s Demon in Quantum Mechanics

Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 269
Author(s):  
Orly Shenker ◽  
Meir Hemmo
Keyword(s):  
Quantum Mechanics ◽  
Thought Experiment ◽  
Classical Mechanics ◽  
Second Law Of Thermodynamics ◽  
Quantum Mechanical ◽  
Second Law ◽  
Arrow Of Time ◽  
Maxwell’S Demon ◽  
Counter Example ◽  
Maxwell's Demon

Maxwell’s Demon is a thought experiment devised by J. C. Maxwell in 1867 in order to show that the Second Law of thermodynamics is not universal, since it has a counter-example. Since the Second Law is taken by many to provide an arrow of time, the threat to its universality threatens the account of temporal directionality as well. Various attempts to “exorcise” the Demon, by proving that it is impossible for one reason or another, have been made throughout the years, but none of them were successful. We have shown (in a number of publications) by a general state-space argument that Maxwell’s Demon is compatible with classical mechanics, and that the most recent solutions, based on Landauer’s thesis, are not general. In this paper we demonstrate that Maxwell’s Demon is also compatible with quantum mechanics. We do so by analyzing a particular (but highly idealized) experimental setup and proving that it violates the Second Law. Our discussion is in the framework of standard quantum mechanics; we give two separate arguments in the framework of quantum mechanics with and without the projection postulate. We address in our analysis the connection between measurement and erasure interactions and we show how these notions are applicable in the microscopic quantum mechanical structure. We discuss what might be the quantum mechanical counterpart of the classical notion of “macrostates”, thus explaining why our Quantum Demon setup works not only at the micro level but also at the macro level, properly understood. One implication of our analysis is that the Second Law cannot provide a universal lawlike basis for an account of the arrow of time; this account has to be sought elsewhere.

scholarly journals BLACK HOLES AND THE THIRD LAW OF THERMODYNAMICS

2004 ◽  
Vol 13 (04) ◽  
pp. 739-770 ◽  
Author(s):  
F. BELGIORNO ◽  
M. MARTELLINI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Second Law Of Thermodynamics ◽  
Temperature Limit ◽  
Black Hole Thermodynamics ◽  
Zero Temperature ◽  
The Third ◽  
Third Law Of Thermodynamics ◽  
Third Law ◽  
Extremal Black Holes

We discuss in the framework of black hole thermodynamics some aspects relative to the third law in the case of black holes of the Kerr–Newman family. In the light of the standard proof of the equivalence between the unattainability of the zero temperature and the entropic version of the third law it is remarked that the unattainability has a special character in black hole thermodynamics. Also the zero temperature limit which obtained in the case of very massive black holes is discussed and it is shown that a violation of the entropic version in the charged case occurs. The violation of the Bekenstein–Hawking law in favour of zero entropy SE=0 in the case of extremal black holes is suggested as a natural solution for a possible violation of the second law of thermodynamics. Thermostatic arguments in support of the unattainability are explored, and SE=0 for extremal black holes is shown to be again a viable solution. The third law of black hole dynamics by W. Israel is then interpreted as a further strong corroboration to the picture of a discontinuity between extremal states and non-extremal ones.

scholarly journals Fermi’s Golden Rule and the Second Law of Thermodynamics

2020 ◽  
Vol 50 (11) ◽  
pp. 1509-1540
Author(s):  
D. Braak ◽  
J. Mannhart
Keyword(s):  
Quantum Dynamics ◽  
Transition Probabilities ◽  
Detailed Balance ◽  
Golden Rule ◽  
Second Law Of Thermodynamics ◽  
Optical Systems ◽  
Quantum Mechanical ◽  
Second Law ◽  
Fermi's Golden Rule ◽  
Fermi’S Golden Rule

AbstractWe present a Gedankenexperiment that leads to a violation of detailed balance if quantum mechanical transition probabilities are treated in the usual way by applying Fermi’s “golden rule”. This Gedankenexperiment introduces a collection of two-level systems that absorb and emit radiation randomly through non-reciprocal coupling to a waveguide, as realized in specific chiral quantum optical systems. The non-reciprocal coupling is modeled by a hermitean Hamiltonian and is compatible with the time-reversal invariance of unitary quantum dynamics. Surprisingly, the combination of non-reciprocity with probabilistic radiation processes entails negative entropy production. Although the considered system appears to fulfill all conditions for Markovian stochastic dynamics, such a dynamics violates the Clausius inequality, a formulation of the second law of thermodynamics. Several implications concerning the interpretation of the quantum mechanical formalism are discussed.

scholarly journals A new spin on the Weak Gravity Conjecture

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Lars Aalsma ◽  
Alex Cole ◽  
Gregory J. Loges ◽  
Gary Shiu
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mild Form ◽  
Black String ◽  
Charged Black Holes ◽  
Higher Derivative ◽  
Horizon Geometry ◽  
Weak Gravity ◽  
Extremal Black Holes ◽  
Kaluza Klein

Abstract The mild form of the Weak Gravity Conjecture states that quantum or higher-derivative corrections should decrease the mass of large extremal charged black holes at fixed charge. This allows extremal black holes to decay, unless protected by a symmetry (such as supersymmetry). We reformulate this conjecture as an integrated condition on the effective stress tensor capturing the effect of quantum or higher-derivative corrections. In addition to charged black holes, we also consider rotating BTZ black holes and show that this condition is satisfied as a consequence of the c-theorem, proving a spinning version of the Weak Gravity Conjecture. We also apply our results to a five-dimensional boosted black string with higher-derivative corrections. The boosted black string has a BTZ×S2 near-horizon geometry and, after Kaluza-Klein reduction, describes a four-dimensional charged black hole. Combining the spinning and charged Weak Gravity Conjecture we obtain positivity bounds on the five-dimensional Wilson coefficients that are stronger than those obtained from charged black holes alone.

scholarly journals General theory of large D membranes consistent with second law of thermodynamics

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Arunabha Saha
Keyword(s):  
Black Holes ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Local Form ◽  
Leading Order ◽  
Stationary Black Hole ◽  
Simple Modification ◽  
Entropy Current ◽  
Additional Constraints ◽  
Stationary Membrane

Abstract We write down the most general membrane equations dual to black holes for a general class of gravity theories, up to sub-leading order in 1/D in large D limit. We derive a “minimal” entropy current which satisfies a local form of second law from these membrane equations. We find that consistency with second law requires the membrane equations to satisfy certain constraints. We find additional constraints on the membrane equations from the existence of membrane solutions dual to stationary black holes. Finally we observe a tension between second law and matching with Wald entropy for dual stationary black hole configurations, for the minimal entropy current. We propose a simple modification of the membrane entropy current so that it satisfies second law and also the stationary membrane entropy matches the Wald entropy.

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