Membrane paradigm and entropy of black holes in the Euclidean action approach

It is known that quantum gravitational effects due to virtual black holes and wormholes can exert an important influence by violating global symmetries. These processes have recently been investigated by Kallosh et al., who found, for the heterotic superstring theory, that there is a sufficient suppression of deleterious effects via the Euclidean action S E from the presence of higher-derivative terms occurring as a topological invariant, the Euler characteristic χ, regardless of the precise details of the underlying wormhole solution. Here, we consider this result further, arguing, in the absence of inflation, that there are no large wormholes in the heterotic superstring theory for which the wormhole action per se is large enough, topological suppression being the only possibility. The model-independent superstring axion may be susceptible to these corrections, because, as shown by Witten, it possesses a non-linearly realized, global U(1) symmetry, being a real scalar field coupled to the anomalous term [Formula: see text] from the outset, and they are relevant to the R-parity symmetry. Allowing for the unknown effect of the black holes, however, we conjecture that these quantum gravitational effects produce no observable consequences.

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Study of Confinement/Deconfinement Transition in AdS/QCD with Generalized Warp Factors

Advances in High Energy Physics ◽

10.1155/2014/543526 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Shobhit Sachan

Keyword(s):

Phase Transition ◽

Black Holes ◽

Background Subtraction ◽

Chemical Potential ◽

Potential Versus ◽

Charged Black Holes ◽

Grand Potential ◽

Versus Transition ◽

Euclidean Action ◽

Insight Into

We study analytical solutions of charged black holes and thermally charged AdS with generalized warped factors in Einstein-Maxwell-Dilaton system. We calculate Euclidean action for charged AdS and thermally charged AdS. The actions in both backgrounds are regularized by the method of background subtraction. The study of phase transition between charged black hole and thermally charged AdS gives an insight into the confinement/deconfinement transition. The plots of grand potential versus temperature and chemical potential versus transition temperature are obtained.

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TOPOLOGICAL BLACK HOLES IN BRANS–DICKE–MAXWELL THEORY

International Journal of Modern Physics D ◽

10.1142/s021827180901531x ◽

2009 ◽

Vol 18 (11) ◽

pp. 1773-1783 ◽

Cited By ~ 10

Author(s):

A. SHEYKHI ◽

H. ALAVIRAD

Keyword(s):

Black Holes ◽

Black Hole ◽

Conformal Transformation ◽

Analytic Solution ◽

Black Hole Thermodynamics ◽

Thermodynamic Quantities ◽

Dilaton Gravity ◽

Maxwell Theory ◽

Charged Black Holes ◽

Euclidean Action

We derive a new analytic solution of (n + 1)-dimensional (n ≥ 4) Brans–Dicke–Maxwell theory in the presence of a potential for the scalar field, by applying a conformal transformation to the dilaton gravity theory. Such solutions describe topological charged black holes with unusual asymptotics. We obtain the conserved and thermodynamic quantities through the use of the Euclidean action method. We also study the thermodynamics of the solutions and verify that the conserved and thermodynamic quantities of the solutions satisfy the first law of black hole thermodynamics.

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Cosmological solutions, a new wick-rotation, and the first law of thermodynamics

Journal of High Energy Physics ◽

10.1007/jhep03(2021)293 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

J. Gutowski ◽

T. Mohaupt ◽

G. Pope

Keyword(s):

Black Holes ◽

Internal Energy ◽

Thermodynamic Potential ◽

Euclidean Geometry ◽

De Sitter ◽

Wick Rotation ◽

Maxwell Theory ◽

First Law Of Thermodynamics ◽

Cosmological Solutions ◽

Euclidean Action

Abstract We present a modified implementation of the Euclidean action formalism suitable for studying the thermodynamics of a class of cosmological solutions containing Killing horizons. To obtain a real metric of definite signature, we perform a “triple Wick-rotation” by analytically continuing all spacelike directions. The resulting Euclidean geometry is used to calculate the Euclidean on-shell action, which defines a thermodynamic potential. We show that for the vacuum de Sitter solution, planar solutions of Einstein-Maxwell theory and a previously found class of cosmological solutions of $$ \mathcal{N} $$ N = 2 supergravity, this thermodynamic potential can be used to define an internal energy which obeys the first law of thermodynamics. Our approach is complementary to, but consistent with the isolated horizon formalism. For planar Einstein-Maxwell solutions, we find dual solutions in Einstein-anti-Maxwell theory where the sign of the Maxwell term is reversed. These solutions are planar black holes, rather than cosmological solutions, but give rise, upon a standard Wick-rotation to the same Euclidean action and thermodynamic relations.

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