scholarly journals q-deformed Einstein equations from entropic force

2018 ◽  
Vol 33 (36) ◽  
pp. 1850218 ◽  
Author(s):  
Mustafa Senay ◽  
Salih Kibaroğlu

In this study, we investigate the influences of fermionic q-deformation on the Einstein equations by taking into account of Verlinde’s entropic gravity approach and Strominger’s proposal on quantum black holes. According to Verlinde’s proposal, gravity is interpreted as an entropic force. Moreover, Strominger’s suggestion claims that extremal black holes obey deformed statistics instead of the standard Bose or Fermi statistics. Inspired by Verlinde’s and Strominger’s suggestions, we represent some thermostatistical functions of VPJC-type q-deformed fermion gas model for the high-temperature limit. Applying the Verlinde’s entropic gravity approach to the q-deformed entropy function, q-deformed Einstein equations with the effective cosmological constant are derived. The results obtained in this work are compared with the related works in the literature.

2015 ◽  
Vol 93 (11) ◽  
pp. 1274-1278 ◽  
Author(s):  
Emre Dil

In this study, we consider three independent physical studies and try to combine them to find an interesting result. Ubriaco’s q-deformed bosons and Verlinde’s entropic gravity studies are taken into account to find the deformed Einstein equations for describing the gravitational field of deformed objects, such as, Strominger’s black holes obeying the deformed Bose or Fermi statistics. We consider the gravitation as an entropic force, as in Verlinde’s approach and assume the source of gravitation is the q-deformed bosons of Ubriaco. Consequently, we obtain the deformed Einstein equations for these deformed bosons by considering the gravitation as an entropic force.


2019 ◽  
Vol 34 (31) ◽  
pp. 1950249
Author(s):  
Salih Kibaroğlu ◽  
Mustafa Senay

In this paper, we study thermodynamical contributions to the theory of gravity under the q-deformed boson and fermion gas models. According to Verlinde’s proposal, the law of gravity is not based on a fundamental interaction but it emerges as an entropic force from the changes of entropy associated with the information on the holographic screen. In addition, Strominger shows that the extremal quantum black holes obey neither boson nor fermion statistics, but they obey deformed statistic. Using these notions, we find q-deformed entropy and temperature functions. We also present the contributions that come from the q-deformed model to the Poisson equation, Newton’s law of gravity and Einstein’s field equations.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Joonho Kim ◽  
Seok Kim ◽  
Jaewon Song

Abstract We study the asymptotic behavior of the (modified) superconformal index for 4d $$ \mathcal{N} $$ N = 1 gauge theory. By considering complexified chemical potential, we find that the ‘high-temperature limit’ of the index can be written in terms of the conformal anomalies 3c − 2a. We also find macroscopic entropy from our asymptotic free energy when the Hofman-Maldacena bound 1/2 < a/c < 3/2 for the interacting SCFT is satisfied. We study $$ \mathcal{N} $$ N = 1 theories that are dual to AdS5 × Yp,p and find that the Cardy limit of our index accounts for the Bekenstein-Hawking entropy of large black holes.


2017 ◽  
Vol 32 (15) ◽  
pp. 1750080 ◽  
Author(s):  
Emre Dil

In this study, to investigate the very nature of quantum black holes, we try to relate three independent studies: (q, p)-deformed Fermi gas model, Verlinde’s entropic gravity proposal and Strominger’s quantum black holes obeying the deformed statistics. After summarizing Strominger’s extremal quantum black holes, we represent the thermostatistics of (q, p)-fermions to reach the deformed entropy of the (q, p)-deformed Fermi gas model. Since Strominger’s proposal claims that the quantum black holes obey deformed statistics, this motivates us to describe the statistics of quantum black holes with the (q, p)-deformed fermions. We then apply the Verlinde’s entropic gravity proposal to the entropy of the (q, p)-deformed Fermi gas model which gives the two-parameter deformed Einstein equations describing the gravitational field equations of the extremal quantum black holes obeying the deformed statistics. We finally relate the obtained results with the recent study on other modification of Einstein equations obtained from entropic quantum corrections in the literature.


Universe ◽  
2020 ◽  
Vol 6 (11) ◽  
pp. 210
Author(s):  
Ismael Ayuso ◽  
Diego Sáez-Chillón Gómez

Extremal cosmological black holes are analysed in the framework of the most general second order scalar-tensor theory, the so-called Horndeski gravity. Such extremal black holes are a particular case of Schwarzschild-De Sitter black holes that arises when the black hole horizon and the cosmological one coincide. Such metric is induced by a particular value of the effective cosmological constant and is known as Nariai spacetime. The existence of this type of solutions is studied when considering the Horndeski Lagrangian and its stability is analysed, where the so-called anti-evaporation regime is studied. Contrary to other frameworks, the radius of the horizon remains stable for some cases of the Horndeski Lagrangian when considering perturbations at linear order.


2004 ◽  
Vol 13 (04) ◽  
pp. 739-770 ◽  
Author(s):  
F. BELGIORNO ◽  
M. MARTELLINI

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.


2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Andres Anabalon ◽  
Dumitru Astefanesei ◽  
Antonio Gallerati ◽  
Mario Trigiante

Abstract In this article we study a family of four-dimensional, $$ \mathcal{N} $$ N = 2 supergravity theories that interpolates between all the single dilaton truncations of the SO(8) gauged $$ \mathcal{N} $$ N = 8 supergravity. In this infinitely many theories characterized by two real numbers — the interpolation parameter and the dyonic “angle” of the gauging — we construct non-extremal electrically or magnetically charged black hole solutions and their supersymmetric limits. All the supersymmetric black holes have non-singular horizons with spherical, hyperbolic or planar topology. Some of these supersymmetric and non-extremal black holes are new examples in the $$ \mathcal{N} $$ N = 8 theory that do not belong to the STU model. We compute the asymptotic charges, thermodynamics and boundary conditions of these black holes and show that all of them, except one, introduce a triple trace deformation in the dual theory.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Ben Craps ◽  
Marine De Clerck ◽  
Philip Hacker ◽  
Kévin Nguyen ◽  
Charles Rabideau

Abstract Out-of-time-order correlators (OTOCs) that capture maximally chaotic properties of a black hole are determined by scattering processes near the horizon. This prompts the question to what extent OTOCs display chaotic behaviour in horizonless microstate geometries. This question is complicated by the fact that Lyapunov growth of OTOCs requires nonzero temperature, whereas constructions of microstate geometries have been mostly restricted to extremal black holes.In this paper, we compute OTOCs for a class of extremal black holes, namely maximally rotating BTZ black holes, and show that on average they display “slow scrambling”, characterized by cubic (rather than exponential) growth. Superposed on this average power-law growth is a sawtooth pattern, whose steep parts correspond to brief periods of Lyapunov growth associated to the nonzero temperature of the right-moving degrees of freedom in a dual conformal field theory.Next we study the extent to which these OTOCs are modified in certain “superstrata”, horizonless microstate geometries corresponding to these black holes. Rather than an infinite throat ending on a horizon, these geometries have a very deep but finite throat ending in a cap. We find that the superstrata display the same slow scrambling as maximally rotating BTZ black holes, except that for large enough time intervals the growth of the OTOC is cut off by effects related to the cap region, some of which we evaluate explicitly.


2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Mehrdad Mirbabayi

Abstract We propose a Euclidean preparation of an asymptotically AdS2 spacetime that contains an inflating dS2 bubble. The setup can be embedded in a four dimensional theory with a Minkowski vacuum and a false vacuum. AdS2 approximates the near horizon geometry of a two-sided near-extremal Reissner-Nordström black hole, and the two sides can connect to the same Minkowski asymptotics to form a topologically nontrivial worm- hole geometry. Likewise, in the false vacuum the near-horizon geometry of near-extremal black holes is approximately dS2 times 2-sphere. We interpret the Euclidean solution as describing the decay of an excitation inside the wormhole to a false vacuum bubble. The result is an inflating region inside a non-traversable asymptotically Minkowski wormhole.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Gourav Banerjee ◽  
Sudip Karan ◽  
Binata Panda

Abstract We study one-loop covariant effective action of “non-minimally coupled” $$ \mathcal{N} $$ N = 1, d = 4 Einstein-Maxwell supergravity theory by heat kernel tool. By fluctuating the fields around the classical background, we study the functional determinant of Laplacian differential operator following Seeley-DeWitt technique of heat kernel expansion in proper time. We then compute the Seeley-DeWitt coefficients obtained through the expansion. A particular Seeley-DeWitt coefficient is used for determining the logarithmic correction to Bekenstein-Hawking entropy of extremal black holes using quantum entropy function formalism. We thus determine the logarithmic correction to the entropy of Kerr-Newman, Kerr and Reissner-Nordström black holes in “non-minimally coupled” $$ \mathcal{N} $$ N = 1, d = 4 Einstein-Maxwell supergravity theory.


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