scholarly journals Exploring Alternatives to the Hamiltonian Calculation of the Ashtekar-Olmedo-Singh Black Hole Solution

2021 ◽  
Vol 8 ◽  
Author(s):  
Alejandro García-Quismondo ◽  
Guillermo A. Mena Marugán
Keyword(s):  
Black Hole ◽  
Phase Space ◽  
Black Hole Solution ◽  
Equations Of Motion ◽  
Hamiltonian Formalism ◽  
Quantum Geometry ◽  
Dynamical Equations ◽  
Constants Of Motion ◽  
Geometry Effects ◽  
Hole Model

In this article, we reexamine the derivation of the dynamical equations of the Ashtekar-Olmedo-Singh black hole model in order to determine whether it is possible to construct a Hamiltonian formalism where the parameters that regulate the introduction of quantum geometry effects are treated as true constants of motion. After arguing that these parameters should capture contributions from two distinct sectors of the phase space that had been considered independent in previous analyses in the literature, we proceed to obtain the corresponding equations of motion and analyze the consequences of this more general choice. We restrict our discussion exclusively to these dynamical issues. We also investigate whether the proposed procedure can be reconciled with the results of Ashtekar, Olmedo, and Singh, at least in some appropriate limit.

scholarly journals Black Hole Solution of Einstein-Born-Infeld-Yang-Mills Theory

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Kun Meng ◽  
Da-Bao Yang ◽  
Zhan-Ning Hu
Keyword(s):  
Phase Transition ◽  
Black Hole ◽  
Phase Space ◽  
Cosmological Constant ◽  
Black Hole Solution ◽  
Extended Phase Space ◽  
Extended Phase ◽  
Yang Mills ◽  
First Law Of Thermodynamics ◽  
Dimensional Black Hole

A new four-dimensional black hole solution of Einstein-Born-Infeld-Yang-Mills theory is constructed; several degenerated forms of the black hole solution are presented. The related thermodynamical quantities are calculated, with which the first law of thermodynamics is checked to be satisfied. Identifying the cosmological constant as pressure of the system, the phase transition behaviors of the black hole in the extended phase space are studied.

scholarly journals TACHYON EFFECTS ON THE TWO-DIMENSIONAL BLACK HOLE GEOMETRY

1995 ◽  
Vol 10 (18) ◽  
pp. 1277-1286 ◽  
Author(s):  
G.A. DIAMANDIS ◽  
B.C. GEORGALAS ◽  
E. PAPANTONOPOULOS
Keyword(s):  
Exact Solution ◽  
Black Hole ◽  
Black Hole Solution ◽  
Equations Of Motion ◽  
Tree Level ◽  
Two Dimensional ◽  
Full System ◽  
Dimensional Black Hole ◽  
Hole Geometry ◽  
Hole Structure

We study solutions of the tree level string effective action in the presence of the tachyon mode. In the case of static fields we find numerically that the full system has a black hole solution with the tachyon regular at the horizon. We also find a nonstatic exact solution of the equations of motion having a black hole structure with a past singularity.

scholarly journals Spatially homogeneous black hole solutions in $$z=4$$ Hořava–Lifshitz gravity in $$(4+1)$$ dimensions with Nil geometry and $$H^2\times R$$ horizons

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
F. Naderi ◽  
A. Rezaei-Aghdam ◽  
Z. Mahvelati-Shamsabadi
Keyword(s):  
Black Hole ◽  
Black Hole Solution ◽  
Three Dimensional ◽  
Hamiltonian Formalism ◽  
Coupling Constant ◽  
Especial Case ◽  
Gravity Equations ◽  
Spatially Homogeneous ◽  
Black Hole Solutions ◽  
Bianchi Types

AbstractIn this paper, we present two new families of spatially homogeneous black hole solution for $$z=4$$ z = 4 Hořava–Lifshitz Gravity equations in $$(4+1)$$ ( 4 + 1 ) dimensions with general coupling constant $$\lambda $$ λ and the especial case $$\lambda =1$$ λ = 1 , considering $$\beta =-1/3$$ β = - 1 / 3 . The three-dimensional horizons are considered to have Bianchi types II and III symmetries, and hence the horizons are modeled on two types of Thurston 3-geometries, namely the Nil geometry and $$H^2\times R$$ H 2 × R . Being foliated by compact 3-manifolds, the horizons are neither spherical, hyperbolic, nor toroidal, and therefore are not of the previously studied topological black hole solutions in Hořava–Lifshitz gravity. Using the Hamiltonian formalism, we establish the conventional thermodynamics of the solutions defining the mass and entropy of the black hole solutions for several classes of solutions. It turned out that for both horizon geometries the area term in the entropy receives two non-logarithmic negative corrections proportional to Hořava–Lifshitz parameters. Also, we show that choosing some proper set of parameters the solutions can exhibit locally stable or unstable behavior.

scholarly journals Fuzzy dark matter black holes and droplets

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
D. Batic ◽  
D. Asem Abuhejleh ◽  
M. Nowakowski
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Black Hole Solution ◽  
Mass Parameter ◽  
Radial Pressure ◽  
Momentum Tensor ◽  
Anisotropic Fluid ◽  
De Sitter ◽  
Hole Model

AbstractWe consider the possibility of having Dark Matter (DM) black holes motivated by the Einasto density profile. This generalizes both the noncommutative mini black hole model and allows DM to enter as the matter constituent which makes up the black hole. We show that it is possible to construct a black hole solution for each value of the Einasto index and for different values of the mass parameter, provided that the we work with the energy–momentum tensor of an anisotropic fluid. In particular, we achieve that by first considering the equation of state (EOS) $$p_r=-\rho $$ p r = - ρ . It turns out that the corresponding black hole solution exhibits a horizon structure similar to that of a Reissner–Nordström black hole and the central singularity is replaced by a regular de Sitter core. We also show that if the previous EOS is replaced by a nonlocal one, it is possible to construct a self-gravitating fuzzy DM droplet but also in this case, the radial pressure is negative. Finally, we contemplate scenarios of different dark matter black holes with moderate mass values which could have formed in galaxies. In particular, we probe the possibility whether such black holes could also be the central galactic objects.

scholarly journals NON-ABELIAN PROCA MODEL BASED ON THE IMPROVED BFT FORMALISM

1998 ◽  
Vol 13 (13) ◽  
pp. 2179-2199 ◽  
Author(s):  
MU-IN PARK ◽  
YOUNG-JAI PARK
Keyword(s):  
Phase Space ◽  
Equations Of Motion ◽  
Hamiltonian Formalism ◽  
Difficult Problem ◽  
Lagrangian Formulation ◽  
Exponential Form ◽  
Extended Phase ◽  
Physical Variables ◽  
Correction Terms ◽  
Insight Into

We present the newly improved Batalin–Fradkin–Tyutin (BFT) Hamiltonian formalism and the generalization to the Lagrangian formulation, which provide a much more simple and transparent insight into the usual BFT method, with application to the non-Abelian Proca model, which has been a difficult problem in the usual BFT method. The infinite terms of the effectively first class contraints can be made to be the regular power series forms by an ingenious choice of Xαβ and ωαβ matrices. In this new method, the first class Hamiltonian, which also needs infinite correction terms, is obtained simply by replacing the original variables in the original Hamiltonian with the BFT physical variables. Remarkably, all the infinite correction terms can be expressed in the compact exponential form. We also show that in our model the Poisson brackets of the BFT physical variables in the extended phase space have the same structure as the Dirac brackets of the original phase space variables. With the help of both our newly developed Lagrangian formulation and Hamilton's equations of motion, we obtain the desired classical Lagrangian corresponding to the first class Hamiltonian which can be reduced to the generalized Stückelberg Lagrangian which is a nontrivial conjecture in our infinitely many terms involved in the Hamiltonian and the Lagrangian.

scholarly journals WORMHOLES IN TWO-DIMENSIONAL DILATON GRAVITY

1994 ◽  
Vol 09 (11) ◽  
pp. 959-966 ◽  
Author(s):  
SHIN'ICHI NOJIRI ◽  
ICHIRO ODA
Keyword(s):  
Black Hole ◽  
Black Hole Solution ◽  
Equations Of Motion ◽  
Quantum Corrections ◽  
Two Dimensional ◽  
Dilaton Gravity ◽  
Curvature Singularity ◽  
Wormhole Solution ◽  
Global Event ◽  
Matter Perturbation

It is shown that the general solution of classical equations of motion in two-dimensional dilaton gravity proposed by Callan, Giddings, Harvey and Strominger (CGHS) includes a Lorentzian wormhole solution in addition to a black hole solution. We also show that matter perturbation of the wormhole by a shock wave leads to the formation of a black hole where the curvature singularity is cloaked by the global event horizon. It is also argued that the classical wormhole would be stable against quantum corrections.

scholarly journals Spinning bodies in general relativity

2016 ◽  
Vol 13 (08) ◽  
pp. 1640002 ◽  
Author(s):  
J. W. van Holten
Keyword(s):  
General Relativity ◽  
Energy Momentum Tensor ◽  
Equations Of Motion ◽  
Hamiltonian Formalism ◽  
Momentum Tensor ◽  
Curved Space ◽  
Constants Of Motion ◽  
Spinning Bodies ◽  
Compact Spinning ◽  
Independent Derivation

A covariant Hamiltonian formalism for the dynamics of compact spinning bodies in curved space-time in the test-particle limit is described. The construction allows a large class of Hamiltonians accounting for specific properties and interactions of spinning bodies. The dynamics for a minimal and a specific non-minimal Hamiltonian is discussed. An independent derivation of the equations of motion from an appropriate energy–momentum tensor is provided. It is shown how to derive constants of motion, both background-independent and background-dependent ones.

scholarly journals Distinguishing black holes through their ringing

SURG Journal ◽  
2010 ◽  
Vol 4 (1) ◽  
pp. 87-92
Author(s):  
Shannon Potter ◽  
Luis Lehner
Keyword(s):  
Black Hole ◽  
Gravitational Wave ◽  
Black Hole Solution ◽  
Alternative Explanation ◽  
Quasinormal Modes ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Schwarzschild Black Hole ◽  
Black Hole Spacetime ◽  
Hole Model

A perturbed black hole spacetime emits gravitational waves possessing quasinormal modes that are characteristic of the black hole itself. We use a massless scalar field as an analog to a gravitational wave to find the quasinormal modes emitted by both a Schwarzschild black hole and a new alternative black hole model which places the Schwarzschild black hole in an aether—a zero density, negative pressure perfect fluid. The later model was proposed as an alternative explanation for accelerated cosmic expansion [1]. We construct a computational code to study both systems numerically and obtain the corresponding quasinormal modes. We find that the quasinormal modes of a black hole in an aether are distinguishable from those of a Schwarzschild black hole and so, in principle, gravitational wave observations could be exploited to determine if either black hole solution represents those existing in our universe.

scholarly journals N=2 SUPERSYMMETRY AND STRING-LOOP CORRECTED MAGNETIC BLACK HOLES

2002 ◽  
Vol 17 (06) ◽  
pp. 355-371 ◽  
Author(s):  
MIKHAIL Z. IOFA
Keyword(s):  
Black Hole ◽  
Maxwell Equations ◽  
Black Hole Solution ◽  
Equations Of Motion ◽  
Level Gauge ◽  
Tree Level ◽  
Loop Correction ◽  
Heterotic String Theory ◽  
String Loop ◽  
Gauge Couplings

We study string-loop corrections to magnetic black hole. Four-dimensional theory is obtained by compactification of the heterotic string theory on the manifold K3×T2 or on a suitable orbifold yielding N=1 supersymmetry in 6D. The resulting 4D theory has N=2 local supersymmetry. Prepotential of this theory receives only one-string-loop correction. The tree-level gauge couplings are proportional to the inverse effective string coupling and decrease at small distances from the center of magnetic black hole, so that loop corrections to the gauge couplings are important in this region. We solve the system of Killing spinor equations (conditions for the supersymmetry variations of the fermions to vanish) and Maxwell equations. At the string-tree level, we reproduce the magnetic black hole solution which can also be obtained by solving the system of the Einstein–Maxwell equations and the equations of motion for the moduli. String-loop corrections to the tree-level solution are calculated in the first order in string coupling. The resulting corrections to the metric and dilaton are large at small distances from the center of the black hole. Possible smearing of the singularity at the origin by quantum corrections is discussed.

Dynamics of scalar shell for rotating and charged rotating BTZ black holes

2019 ◽  
Vol 35 (02) ◽  
pp. 1950350 ◽  
Author(s):  
M. Sharif ◽  
Faisal Javed
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Thin Shell ◽  
Equations Of Motion ◽  
Scalar Fields ◽  
Massless Scalar ◽  
Massive Scalar ◽  
Matter Distribution ◽  
Dynamical Equations

This paper studies the dynamics of thin-shell for (2 + 1)-dimensional rotating and charged rotating Bañados–Teitelboim–Zanelli black holes by using Israel thin-shell formalism. We consider the matter distribution located at thin-shell associated with a scalar field and analyze its effects on the dynamics of thin-shell through equations of motion and effective potential. The corresponding dynamical equations are numerically studied for both massless as well as massive scalar fields. For rotating case, the rate of expansion and collapse increases with massless scalar shell but decreases for massive case. For charged rotating, the rate of expansion and collapse decreases by increasing angular momentum for both massless as well as massive case. We conclude that the rate of expansion and collapse of the rotating case is greater than charged rotating black hole.

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