scholarly journals Holographic heat engines coupled with logarithmic U(1) gauge theory

2021 ◽  
Author(s):  
Soodeh Zarepour
Keyword(s):  
Black Holes ◽  
Gauge Theory ◽  
Strong Coupling ◽  
Heat Engine ◽  
Positive Zero ◽  
Maximum Efficiency ◽  
Nonlinearity Parameter ◽  
Heat Engines ◽  
Ads Black Holes ◽  
Negative Constant

In this paper, we study a new class of holographic heat engines via charged AdS black hole solutions of Einstein gravity coupled with logarithmic nonlinear [Formula: see text] gauge theory. So, logarithmic [Formula: see text] AdS black holes with a horizon of positive, zero and negative constant curvatures are considered as a working substance of a holographic heat engine and the corrections to the usual Maxwell field are controlled by nonlinearity parameter [Formula: see text]. The efficiency of an ideal cycle ([Formula: see text]), consisting of a sequence of isobaric [Formula: see text] isochoric [Formula: see text] isobaric [Formula: see text] isochoric processes, is computed using the exact efficiency formula. It is shown that [Formula: see text], with [Formula: see text] the Carnot efficiency (the maximum efficiency available between two fixed temperatures), decreases as we move from the strong coupling regime ([Formula: see text]) to the weak coupling domain ([Formula: see text]). We also obtain analytic relations for the efficiency in the weak and strong coupling regimes in both low and high temperature limits. The efficiency for planar and hyperbolic logarithmic [Formula: see text] AdS black holes is computed and it is observed that efficiency versus [Formula: see text] behaves in the same qualitative manner as the spherical black holes.

scholarly journals Thermodynamics of Riemannian Kerr-AdS black holes in Poincaré gauge theory

2021 ◽  
Vol 816 ◽  
pp. 136242
Author(s):  
M. Blagojević ◽  
B. Cvetković
Keyword(s):  
Black Holes ◽  
Gauge Theory ◽  
Ads Black Holes

Universal Optimization Efficiency for Nonlinear Irreversible Heat Engines

2017 ◽  
Vol 42 (3) ◽  
Author(s):  
Yanchao Zhang ◽  
Juncheng Guo ◽  
Guoxing Lin ◽  
Jincan Chen
Keyword(s):  
Objective Function ◽  
Strong Coupling ◽  
Power Efficiency ◽  
Symmetry Condition ◽  
Maximum Efficiency ◽  
Cycle Model ◽  
Trade Off ◽  
Heat Engines ◽  
Optimization Efficiency ◽  
Universal Expression

AbstractWe introduce a multi-parameter combined objective function of heat engines under the strong coupling and symmetry condition and derive the universal expression of the optimization efficiency. The results obtained show that the optimization efficiency derived from the multi-parameter combined objective function include a variety of optimization efficiencies, such as the efficiency at the maximum power, efficiency at the maximum efficiency-power state, efficiency at the maximum ecological or unified trade-off function, and Carnot efficiency. It is further explained that these results are also suitable for the endoreversible cycle model of the Carnot heat engines operating between two heat reservoirs.

scholarly journals THE STRUCTURE OF ADS BLACK HOLES AND CHERN–SIMONS THEORY IN 2 + 1 DIMENSIONS

1999 ◽  
Vol 14 (04) ◽  
pp. 505-520 ◽  
Author(s):  
SHARMANTHIE FERNANDO ◽  
FREYDOON MANSOURI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gauge Theory ◽  
Excited States ◽  
Simons Theory ◽  
De Sitter ◽  
Sitter Group ◽  
Ads Black Holes ◽  
Chern Simons ◽  
Chern Simons Theory

We study anti-de Sitter black holes in 2 + 1 dimensions in terms of Chern–Simons gauge theory of the anti-de Sitter group coupled to a source. Taking the source to be an anti-de Sitter state specified by its Casimir invariants, we show how all the relevant features of the black hole are accounted for. The requirement that the source be a unitary representation leads to a discrete tower of excited states which provide a microscopic model for the black hole.

scholarly journals Holographic heat engines and static black holes: A general efficiency formula

2019 ◽  
Vol 28 (02) ◽  
pp. 1950030 ◽  
Author(s):  
Felipe Rosso
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Upper Bound ◽  
Heat Engine ◽  
Thermodynamic System ◽  
Ideal Gas ◽  
Heat Flows ◽  
Heat Engines ◽  
Static Black Hole

Starting from simple observations regarding heat flows for static black holes (or any thermodynamic system with [Formula: see text]), we get inequalities which restrict their change in energy and adiabatic curves in the [Formula: see text] plane. From these observations, we then derive an exact efficiency formula for virtually any holographic heat engine defined by a cycle in the [Formula: see text] plane, whose working substance is a static black hole. Moreover, we get an upper bound for its efficiency and show that for a certain class of black holes, this bound is universal and achieved by an “ideal gas” hole. Finally, we compute exact efficiencies for some particular and new engines.

scholarly journals AdS black holes with higher derivative corrections in presence of string cloud

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Tanay K. Dey ◽  
Subir Mukhopadhyay
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gauge Theory ◽  
Binding Energy ◽  
Parameter Space ◽  
Bonnet Gravity ◽  
Higher Derivative ◽  
Ads Black Holes ◽  
Black Hole Solutions

AbstractWe consider asymptotically AdS black hole solutions in Einstein Gauss Bonnet gravity in presence of string clouds. As in the case of black hole solutions in Gauss Bonnet gravity, it admits three black hole solutions in presence of string clouds as well within a region of the parameter space. Using holography, we have studied the quark–antiquark distance and binding energy in the dual gauge theory.

scholarly journals Effect of Finite-Size Heat Source’s Heat Capacity on the Efficiency of Heat Engine

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 1002 ◽  
Author(s):  
Yu-Han Ma
Keyword(s):  
Black Holes ◽  
Heat Capacity ◽  
Temperature Difference ◽  
Initial Temperature ◽  
Heat Engine ◽  
Finite Size ◽  
Practical Significance ◽  
Total Output ◽  
Heat Sources ◽  
Heat Engines

Heat engines used to output useful work have important practical significance, which, in general, operate between heat baths of infinite size and constant temperature. In this paper, we study the efficiency of a heat engine operating between two finite-size heat sources with initial temperature difference. The total output work of such heat engine is limited due to the finite heat capacity of the sources. We firstly investigate the effects of different heat capacity characteristics of the sources on the heat engine’s efficiency at maximum work (EMW) in the quasi-static limit. Moreover, it is found that the efficiency of the engine operating in finite-time with maximum power of each cycle is achieved follows a simple universality as η=ηC/4+OηC2, where ηC is the Carnot efficiency determined by the initial temperature of the sources. Remarkably, when the heat capacity of the heat source is negative, such as the black holes, we show that the heat engine efficiency during the operation can surpass the Carnot efficiency determined by the initial temperature of the heat sources. It is further argued that the heat engine between two black holes with vanishing initial temperature difference can be driven by the energy fluctuation. The corresponding EMW is proved to be ηMW=2−2.

scholarly journals A bestiary of black holes on the conifold with fluxes

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Alex Buchel
Keyword(s):  
Black Holes ◽  
Phase Transitions ◽  
Gauge Theory ◽  
Symmetry Breaking ◽  
Strong Coupling ◽  
Chiral Symmetry ◽  
Thermal State ◽  
Chiral Symmetry Breaking ◽  
Comprehensive Analysis ◽  
Thermal States

Abstract We present a comprehensive analysis of the black holes on warped deformed conifold with fluxes in Type IIB supergravity. These black holes realize the holographic dual to thermal states of the $$ \mathcal{N} $$ N = 1 supersymmetric SU(N) × SU(N + M) cascading gauge theory of Klebanov et al. [1, 2] on round S3. There are three distinct mass scales in the theory: the strong coupling scale Λ of the cascading gauge theory, the compactification scale μ = 1/L3 (related to the S3 radius L3) and the temperature T of a thermal state. Depending on Λ, μ and T, there is an intricate pattern of confinement/deconfinement (Hawking-Page) and the chiral symmetry breaking phase transitions. In the S3 → ℝ3 decompactification limit, i.e., μ → 0, we recover the Klebanov-Tseytlin [3] and the Klebanov-Strassler [4] black branes.

scholarly journals Effects of a string cloud on the criticality and efficiency of AdS black holes as heat engines

2018 ◽  
Vol 78 (10) ◽  
Author(s):  
J. P. Morais Graça ◽  
Iarley P. Lobo ◽  
Valdir B. Bezerra ◽  
H. Moradpour
Keyword(s):  
Black Holes ◽  
Heat Engines ◽  
Ads Black Holes
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