PARTICLE PRODUCTION BY THE FORMATION OF A GLOBAL MONOPOLE

1991 ◽  
Vol 06 (20) ◽  
pp. 3613-3623 ◽  
Author(s):  
CARLOS O. LOUSTO
Keyword(s):  
Phase Transition ◽  
Black Hole ◽  
Gravitational Field ◽  
Scalar Field ◽  
Particle Production ◽  
Mean Value ◽  
Global Symmetry ◽  
Global Monopole ◽  
Order Of Magnitude ◽  
The Mean

We study pair production by the changing gravitational field of a global monopole during its formation in the very early universe after the breaking of a global symmetry. We obtain a result of the same order of magnitude as in the case of gauge strings ρ~(Gη2)2/τ4, where η is the mean value of the scalar field and τ is the time at which the phase transition occurs. We also discuss how a global monopole inside a mini-black-hole affects its final stages of evolution. We find that neither the Hawking temperature nor the entropy-area relation is essentially modified by the presence of the monopole.

scholarly journals Joule–Thomson expansion in AdS black hole with a global monopole

2018 ◽  
Vol 33 (35) ◽  
pp. 1850210 ◽  
Author(s):  
C. L. Ahmed Rizwan ◽  
A. Naveena Kumara ◽  
Deepak Vaid ◽  
K. M. Ajith
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Black Hole ◽  
Phase Space ◽  
Van Der Waals ◽  
Extended Phase Space ◽  
Global Monopole ◽  
Van Der Waals Gas ◽  
Extended Phase ◽  
Ads Black Holes

In this paper, we investigate the Joule–Thomson effects of AdS black holes with a global monopole. We study the effect of the global monopole parameter [Formula: see text] on the inversion temperature and isenthalpic curves. The obtained result is compared with Joule–Thomson expansion of van der Waals fluid, and the similarities were noted. Phase transition occuring in the extended phase space of this black hole is analogous to that in van der Waals gas. Our study shows that global monopole parameter [Formula: see text] plays a very important role in Joule–Thomson expansion.

Reduced conformal geometrodynamics

2020 ◽  
Vol 35 (02n03) ◽  
pp. 2040023 ◽  
Author(s):  
Andrej B. Arbuzov ◽  
Alexander E. Pavlov
Keyword(s):  
Gravitational Field ◽  
Dynamical Systems ◽  
Coordinate System ◽  
Tangent Space ◽  
Equations Of Motion ◽  
Mean Value ◽  
Hamiltonian Reduction ◽  
Square Root ◽  
The Mean ◽  
Static Background

The global time in geometrodynamics is defined in a covariant under diffeomorphisms form. An arbitrary static background metric is taken in the tangent space. The global intrinsic time is identified with the mean value of the logarithm of the square root of the ratio of the metric determinants. The procedures of the Hamiltonian reduction and deparametrization of dynamical systems are implemented. The reduced Hamiltonian equations of motion of gravitational field in semi-geodesic coordinate system are written.

scholarly journals DISCUSSION ON SOME CHARACTERISTICS OF CHARGED BRANE-WORLD BLACK HOLES

2009 ◽  
Vol 24 (04) ◽  
pp. 719-739 ◽  
Author(s):  
M. KALAM ◽  
F. RAHAMAN ◽  
A. GHOSH ◽  
B. RAYCHAUDHURI
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Field ◽  
Scalar Field ◽  
Brane World ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Effective Potentials ◽  
Test Particles ◽  
Jacobi Formalism

Several physical natures of charged brane-world black holes are investigated. Firstly, the timelike and null geodesics of the charged brane-world black holes are presented. We also analyze all the possible motions by plotting the effective potentials for various parameters for circular and radial geodesics. Secondly, we investigate the motion of test particles in the gravitational field of the charged brane-world black holes using the Hamilton–Jacobi formalism. We consider charged and uncharged test particles and examine their behavior in both static and nonstatic cases. Thirdly, the thermodynamics of the charged brane-world black holes are studied. Finally, it is shown that there is no phenomenon of superradiance for an incident massless scalar field for such a black hole.

Liquid helium films. I. The thickness of the film

1950 ◽  
Vol 203 (1072) ◽  
pp. 119-132 ◽  
Keyword(s):  
Liquid Helium ◽  
Dynamic Method ◽  
Mean Value ◽  
Helium Films ◽  
Helium Ii ◽  
Experimental Factor ◽  
Order Of Magnitude ◽  
The Mean

The thickness ( d ) of the helium II film and its variation with height ( H ) and temperature were measured by a dynamic method involving the oscillations of a meniscus in a capillary. The variation with height could be represented only approximately by the equation d = k/H n , as the effective value of n was greater at smaller values of H . The mean value of n over a range of heights from 0·5 to 5 cm. was 0·14, which is appreciably smaller than the values predicted by the theories so far advanced to explain the formation of the film. The order of magnitude of k was 2 x 10 -6 cm., but it varied slightly with the nature of the surface or some other experimental factor.

A holographic superconductor model with higher correction terms

2015 ◽  
Vol 30 (13) ◽  
pp. 1550069
Author(s):  
Yan Peng ◽  
Guohua Liu
Keyword(s):  
Phase Transition ◽  
Black Hole ◽  
Scalar Field ◽  
Model Parameters ◽  
Holographic Superconductor ◽  
Transition Diagram ◽  
Holographic Superconductors ◽  
Black Hole Background ◽  
Correction Terms ◽  
Matter Fields

We study general models for holographic superconductors with higher correction terms of the scalar field in the four-dimensional AdS black hole background including the matter fields' backreaction on the metric. We explore the effects of the model parameters on the scalar condensation and find that different values of model parameters can determine the order of phase transitions. Moreover, we find that the higher correction terms provide richer physics in the phase transition diagram.

scholarly journals On the Accuracy of Error Propagation Calculations by Analytic Formulas Obtained for the Inverse Transformation

2019 ◽  
Vol 64 (3) ◽  
pp. 217
Author(s):  
V. I. Romanenko ◽  
N. V. Kornilovska
Keyword(s):  
Error Propagation ◽  
Random Variable ◽  
Mean Value ◽  
Inverse Transformation ◽  
First Order ◽  
Order Of Magnitude ◽  
The Mean ◽  
Normally Distributed

The accuracy of error propagation calculations is estimated for the transformation x → y = f(x) of the normally distributed random variable x. The estimation is based on the formulas for the error propagation obtained for the inverse transformation y → x of the normally distributed random variable y. In the general case, the calculation accuracy for the mean value and the variance of the random variable y is shown to be of the first order of magnitude in the variance of the random variable x.

scholarly journals On the stability of the scalar field in the gravitational field of a rotating (Kerr-) black hole

2010 ◽  
Author(s):  
Reinhard Horst Beyer ◽  
H. A. Morales-Tecotl ◽  
L. A. Urena-Lopez ◽  
R. Linares-Romero ◽  
H. H. Garcia-Compean
Keyword(s):  
Black Hole ◽  
Gravitational Field ◽  
Scalar Field ◽  
Kerr Black Hole ◽  
The Stability

scholarly journals LATE-TIME TAIL OF A COUPLED SCALAR FIELD IN THE BACKGROUND OF A BLACK HOLE WITH A GLOBAL MONOPOLE

2008 ◽  
Vol 23 (05) ◽  
pp. 359-369 ◽  
Author(s):  
SONGBAI CHEN ◽  
JILIANG JING
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Scalar Fields ◽  
Massless Scalar ◽  
Late Time ◽  
Massless Scalar Field ◽  
Global Monopole ◽  
Massive Scalar Field ◽  
Gravitational Fields ◽  
Field Decay

Using the technique of spectral decomposition, we investigated the late-time tails of massless and massive coupled scalar fields in the background of a black hole with a global monopole. We found that due to the existence of the coupling between the scalar and gravitational fields, the massless scalar field decay faster at timelike infinity i+, and so does the massive one in the intermediate late time. But the asymptotically late-time tail for the massive scalar field is not affected and its decay rate is still t-5/6.

Sign in / Sign up

Export Citation Format

Share Document