scholarly journals GENERAL BPS BLACK HOLES IN FIVE DIMENSIONS

1998 ◽  
Vol 13 (03) ◽  
pp. 239-252 ◽  
Author(s):  
W. A. SABRA
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Phase Transitions ◽  
Moduli Space ◽  
Arbitrary Number ◽  
Five Dimensions ◽  
Geometry Structure ◽  
Static Black Hole ◽  
Hole Configuration ◽  
M Theory

An algorithm for constructing general static black hole configuration for the theory of N=2, d= 5 supergravity coupled to an arbitrary number of Abelain vector multiplets is given. The underlying very special geometry structure plays a major role in this construction. From the viewpoint of M-theory compactified on a Calabi–Yau threefold, these black holes are identified with BPS winding states of the membrane around two-cycles of the Calabi–Yau threefold, and thus are of importance in the probing of the phase transitions in the moduli space of M-theory compactified on a Calabi–Yau threefold.

scholarly journals Black hole shadows in M-theory scenarios

2021 ◽  
Vol 30 (04) ◽  
pp. 2150026
Author(s):  
A. Belhaj ◽  
M. Benali ◽  
A. El Balali ◽  
W. El Hadri ◽  
H. El Moumni ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Event Horizon ◽  
Moduli Space ◽  
Emission Rate ◽  
Rotation Parameter ◽  
High Energies ◽  
Energy Emission ◽  
M Theory

We study the shadows of four-dimensional black holes in M-theory inspired models. We first inspect the influence of M2-branes on such optical aspects for nonrotating solutions. In particular, we show that the M2-brane number can control the circular shadow size. This geometrical behavior is distorted for rotating solutions exhibiting cardioid shapes in certain moduli space regions. Implementing a rotation parameter, we analyze the geometrical shadow deformations. Among others, we recover the circular behaviors for a large M2-brane number. Investigating the energy emission rate at high energies, we find, in a well-defined approximation, that the associated peak decreases with the M2-brane number. Moreover, we investigate a possible connection with observations (from Event Horizon Telescope or future devices) from a particular M-theory compactification by deriving certain constraints on the M[Formula: see text]-brane number in the light of the [Formula: see text] observational parameters.

Slowly rotating black holes with nonlinear electrodynamics in five dimensions

2014 ◽  
Vol 23 (11) ◽  
pp. 1450095 ◽  
Author(s):  
S. H. Hendi ◽  
M. Sepehri Rad
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Einstein Gravity ◽  
Rotation Parameter ◽  
Nonlinear Electrodynamics ◽  
Five Dimensions ◽  
Angular Momenta ◽  
Static Black Hole ◽  
Rotating Black Holes ◽  
Black Hole Solutions

Employing linear order perturbation theory with the rotation parameter as the perturbative parameter, we obtain asymptotically AdS slowly rotating black hole solutions in the Einstein gravity with Born–Infeld (BI) type nonlinear electrodynamics (NED). We start from asymptotically AdS static black hole solutions coupled to BI type NED in five dimensions. Then, we consider the effect of adding a small amount of angular momenta to the seed solutions. Finally, we investigate the geometry and thermodynamic properties of the solutions.

scholarly journals Phase transition and shadow behaviors of quintessential black holes in M-theory/superstring inspired models

2021 ◽  
Vol 36 (08n09) ◽  
pp. 2150057
Author(s):  
A. Belhaj ◽  
A. El Balali ◽  
W. El Hadri ◽  
Y. Hassouni ◽  
E. Torrente-Lujan
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Black Hole ◽  
Optical Properties ◽  
Phase Transitions ◽  
Dark Energy ◽  
Cosmological Constant ◽  
Chemical Potential ◽  
State Parameter ◽  
M Theory

We study [Formula: see text]-dimensional black holes surrounded by dark energy (DE), embedded in [Formula: see text]-dimensional M-theory/superstring inspired models having [Formula: see text] space–time where [Formula: see text]. We focus first on the thermodynamical Hawking–Page phase transitions, whose microscopical origin is linked to [Formula: see text] coincident [Formula: see text]-branes supposed to live in such inspired models. Interpreting the cosmological constant as the number of colors, we compute various thermodynamical quantities in terms of the brane number, the entropy and the DE contribution. Calculating the ordinary chemical potential conjugated to the number of colors, we show that a generic black hole is more stable for a larger number of branes in lower dimensions. In the presence of DE, however, we find that the DE state parameter [Formula: see text] takes particular values, for [Formula: see text] models, providing nontrivial phase transitions. Then, we examine some optical properties. Concretely, we investigate shadow behaviors of quintessential black holes in terms of [Formula: see text]-brane physics. In terms of certain ratios, we find similar behaviors for critical quantities and shadow radius.

scholarly journals ENERGY EXTRACTION FROM GRAVITATIONAL COLLAPSE TO STATIC BLACK HOLES

2003 ◽  
Vol 12 (01) ◽  
pp. 121-127 ◽  
Author(s):  
REMO RUFFINI ◽  
LUCA VITAGLIANO
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Extraction Process ◽  
Maximum Efficiency ◽  
Energy Extraction ◽  
Mass Energy ◽  
Classical Level ◽  
Static Black Hole ◽  
Exact Analytic Expression ◽  
Analytic Expression

The mass-energy formula of black holes implies that up to 50% of the energy can be extracted from a static black hole. Such a result is reexamined using the recently established analytic formulas for the collapse of a shell and the expression for the irreducible mass of a static black hole. It is shown that the efficiency of energy extraction process during the formation of the black hole is linked in an essential way to the gravitational binding energy, the formation of the horizon and the reduction of the kinetic energy of implosion. Here a maximum efficiency of 50% in the extraction of the mass energy is shown to be generally attainable in the collapse of a spherically symmetric shell: surprisingly this result holds as well in the two limiting cases of the Schwarzschild and extreme Reissner–Nordström space–times. Moreover, the analytic expression recently found for the implosion of a spherical shell to an already formed black hole leads to a new exact analytic expression for the energy extraction which results in an efficiency strictly less than 100% for any physical implementable process. There appears to be no incompatibility between General Relativity and Thermodynamics at this classical level.

scholarly journals Black hole solutions in gravity with nonminimal derivative coupling and nonlinear material fields

2020 ◽  
Vol 29 (03) ◽  
pp. 2050025 ◽  
Author(s):  
Mykola M. Stetsko
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Electromagnetic Field ◽  
Nonlinear Material ◽  
Derivative Coupling ◽  
First Law Of Thermodynamics ◽  
Tensor Theory ◽  
Static Black Hole ◽  
Nonlinear Lagrangians ◽  
Black Hole Solutions

Scalar–tensor theory of gravity with nonlinear electromagnetic field, minimally coupled to gravity is considered and static black hole solutions are obtained. Namely, power-law and Born–Infeld nonlinear Lagrangians for the electromagnetic field are examined. Since the cosmological constant is taken into account, it allowed us to investigate the so-called topological black holes. Black hole thermodynamics is studied, in particular temperature of the black holes is calculated and examined and the first law of thermodynamics is obtained with help of Wald’s approach.

scholarly journals Distributions of extremal black holes in Calabi-Yau compactifications

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
George Hulsey ◽  
Shamit Kachru ◽  
Sungyeon Yang ◽  
Max Zimet
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Moduli Space ◽  
Black Hole Horizon ◽  
Extremal Black Hole ◽  
Vector Multiplet ◽  
Horizon Area ◽  
Extremal Black Holes

Abstract We study non-supersymmetric extremal black hole excitations of 4d $$ \mathcal{N} $$ N = 2 supersymmetric string vacua arising from compactification on Calabi-Yau threefolds. The values of the (vector multiplet) moduli at the black hole horizon are governed by the attractor mechanism. This raises natural questions, such as “what is the distribution of attractor points on moduli space?” and “how many attractor black holes are there with horizon area up to a certain size?” We employ tools developed by Denef and Douglas [1] to answer these questions.

Three-dimensional static black hole with Λ and nonlinear electromagnetic fields and its thermodynamics

2019 ◽  
Vol 28 (12) ◽  
pp. 1950160
Author(s):  
M. B. Tataryn ◽  
M. M. Stetsko
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Electromagnetic Fields ◽  
Three Dimensional ◽  
Nonlinear Electrodynamics ◽  
Extended Phase Space ◽  
Field Equations ◽  
Extended Phase ◽  
Dimensional Spacetime ◽  
Static Black Hole

Static black hole with the Power Maxwell invariant (PMI), Born–Infeld (BI), logarithmic (LN), exponential (EN) electromagnetic fields in three-dimensional spacetime with cosmological constant was studied. It was shown that the LN and EN fields represent the Born–Infeld type of nonlinear electrodynamics. It the framework of General Relativity the exact solutions of the field equations were obtained, corresponding thermodynamic functions were calculated and the [Formula: see text] criticality of the black holes in the extended phase-space thermodynamics was investigated.

Dyonic and Magnetic Black Holes with Rational Nonlinear Electrodynamics

2020 ◽  
Author(s):  
Sergey Kruglov
Keyword(s):  
Black Holes ◽  
Heat Capacity ◽  
Black Hole ◽  
Free Energy ◽  
Phase Transitions ◽  
Helmholtz Free Energy ◽  
Magnetic Charge ◽  
The Self ◽  
Nonlinear Electrodynamics ◽  
Dual Case

The principles of causality and unitarity are studied within rational nonlinear electrodynamics proposed earlier. We investigate dyonic and magnetized black holes and show that in the self-dual case, when the electric charge equals the magnetic charge, corrections to Coulomb's law and Reissner-Nordstrom solutions are absent. In the case of the magnetic black hole, the Hawking temperature, the heat capacity and the Helmholtz free energy are calculated. It is shown that there are second-order phase transitions and it was demonstrated that at some range of parameters the black holes are stable.

scholarly journals General Static N=2 Black Holes

1997 ◽  
Vol 12 (34) ◽  
pp. 2585-2590 ◽  
Author(s):  
W. A. Sabra
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Arbitrary Number ◽  
Harmonic Functions ◽  
Kahler Geometry ◽  
Kähler Potential ◽  
Black Hole Solutions

We find general static BPS black hole solutions for general N=2, d=4 supergravity theories with an arbitrary number of vector multiplets. These solutions are completely specified by the Kähler potential of the underlying special Kähler geometry and a set of constrained harmonic functions.

scholarly journals Black holes with topological charges in Chern-Simons AdS5 supergravity

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Laura Andrianopoli ◽  
Gaston Giribet ◽  
Darío López Díaz ◽  
Olivera Miskovic
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Hamiltonian Formalism ◽  
Naked Singularity ◽  
Extremal Black Hole ◽  
Pure Gauge ◽  
Static Black Hole ◽  
Abelian Field ◽  
Chern Simons ◽  
Spatial Section

Abstract We study static black hole solutions with locally spherical horizons coupled to non-Abelian field in $$ \mathcal{N} $$ N = 4 Chern-Simons AdS5 supergravity. They are governed by three parameters associated to the mass, axial torsion and amplitude of the internal soliton, and two ones to the gravitational hair. They describe geometries that can be a global AdS space, naked singularity or a (non-)extremal black hole. We analyze physical properties of two inequivalent asymptotically AdS solutions when the spatial section at radial infinity is either a 3-sphere or a projective 3-space. An important feature of these 3-parametric solutions is that they possess a topological structure including two SU(2) solitons that wind nontrivially around the black hole horizon, as characterized by the Pontryagin index. In the extremal black hole limit, the solitons’ strengths match and a soliton-antisoliton system unwinds. That limit admits both non-BPS and BPS configurations. For the latter, the pure gauge and non-pure gauge solutions preserve 1/2 and 1/16 of the original supersymmetries, respectively. In a general case, we compute conserved charges in Hamiltonian formalism, finding many similarities with standard supergravity black holes.

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