共查询到20条相似文献,搜索用时 46 毫秒
1.
S. S. Xulu 《International Journal of Theoretical Physics》2007,46(11):2915-2922
In a very well-known paper, Virbhadra’s research group proved that the Weinberg, Papapetrou, Landau and Lifhsitz, and Einstein
energy-momentum complexes “coincide” for all metrics of Kerr–Schild class. A few years later, Virbhadra clarified that this
“coincidence” in fact holds for metrics more general than the Kerr–Schild class. In the present paper, this study is extended
for the Bergmann–Thomson complex and it is proved that this complex also “coincides” with those complexes for a more general
than the Kerr–Schild class metric. 相似文献
2.
Considering the unfixed background space-time and self-gravitational interaction, we view the Hawking radiation of a stationary
Kerr–Newman black hole by Hamilton–Jacobi method. Meanwhile, extending this work to non-stationary black holes, we attempt
to investigate the Hawking radiation of the non-stationary Kerr–Newman black hole. Both of the results show the tunneling
probabilities are related to the change of Bekenstein- Hawking entropy and the radiation spectrums deviate from the purely
thermal one, which is in accordance with the known result. 相似文献
3.
We consider a successful Kerr–Newman formulation of elementary particles and deduce a mass-independent but spin-dependent
short-range force and point out that exactly such an inexplicable force has been experimentally detected. 相似文献
4.
David Christie 《General Relativity and Gravitation》2008,40(1):57-79
A short electromagnetic wavelength approximation is used to obtain general solutions to the Maxwell equations for electromagnetic
radiation in a Kerr–Schild plane gravitational wave metric. Their properties are then investigated for the specific case of
a light beam in a weak, harmonic gravitational wave. 相似文献
5.
Ibrar Hussain 《General Relativity and Gravitation》2011,43(4):1037-1045
Using Lie approximate symmetry methods for differential equations second-order approximate symmetries of the geodesic equations
for the Kerr–Newman-AdS (KN-AdS) spacetime are investigated. For this purpose the KN-AdS metric is considered as a second
perturbation of the AdS metric. A rescaling of the arc length parameter for consistency of the trivial second-order approximate
symmetries of the geodesic equations indicates that the energy in the KN-AdS spacetime has to be rescaled. There is an extra
contribution to the energy of the KN-AdS spacetime due to the cosmological constant. This energy expression is compared with
that for the Kerr–Newman (KN) spacetime. 相似文献
6.
The influence of the orientational fluctuations of the electronic magnetization, which modulate nuclear spin–spin interactions (Suhl–Nakamura and dipole–dipole), on the spin-lattice relaxation of magnetic nuclei with spin I = 1/2 in the magnetically ordered solids has been investigated. It has been shown that this mechanism of the spin-lattice relaxation is less effective in comparison with the process of spin-lattice relaxation caused by the direct fluctuations of hyperfine fields, which appear when there are the fluctuations of electronic magnetization direction. 相似文献
7.
Hajnal Andréka István Németi Christian Wüthrich 《General Relativity and Gravitation》2008,40(9):1809-1823
We investigate Kerr–Newman black holes in which a rotating charged ring-shaped singularity induces a region which contains
closed timelike curves (CTCs). Contrary to popular belief, it turns out that the time orientation of the CTC is opposite to the direction in which the singularity or the ergosphere rotates. In this sense, CTCs “counter-rotate” against the rotating
black hole. We have similar results for all spacetimes sufficiently familiar to us in which rotation induces CTCs. This motivates
our conjecture that perhaps this counter-rotation is not an accidental oddity particular to Kerr–Newman spacetimes, but instead
there may be a general and intuitively comprehensible reason for this. 相似文献
8.
We consider a finite action for a higher dimensional Taub–NUT/Bolt–(A)dS space via the so-called counter term subtraction method. In the limit of high temperature, we show that the Cardy–Verlinde formula holds for the Taub–Bolt–AdS metric and for the specific dimensional Taub–NUT–(A)dS metric, except for the Taub–Bolt–dS metric. 相似文献
9.
Considering the unfixed background space-time and self-gravitational interaction, we review the Hawking radiation of the Kerr–Newman
black hole by Hamilton–Jacobi method. The result shows the tunneling probability is related to the change of Bekenstein–Hawking
entropy and the radiation spectrum deviates from the precisely thermal one, which is in accordance with Parikh and Wilczek’s
result and gives another method to study the Hawking radiation of the black hole. 相似文献
10.
We describe conditions assuring that the Kerr–Schild type solutions of Einstein's equations with pure radiation fields are
asymptotically flat at future null infinity. Such metrics cannot describe “true” gravitational radiation from bounded sources—it
is shown that the Bondi news function vanishes identically. We obtain formulae for the total energy and angular momentum at
ℐ. As an example we consider a non-stationary generalization of the Kerr metric given by Vaidya and Patel. Angular momentum
and total energy are expressed in closed form as functions of retarded time. 相似文献
11.
The Klein–Fock–Gordon equation is solved for a 2D pion moving in a constant uniform magnetic field. A relativistic energy
spectrum is calculated for fixed values of the angular momentum and magnetic field Н. An analysis of the results of these calculations allows us to conclude that the Klein–Fock–Gordon equation, unlike the Schr?dinger
equation, cannot describe the energy of the particle s-state in the magnetic field. It is elucidated that a correction for
the relativistic energy level caused by the constant magnetic field is noticeable for the magnetic field H > 100.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 91–96, March, 2009. 相似文献
12.
Exact interpretation of the NUT parameter becomes possible when a static Schwarzchild mass is immersed in a stationary, source free electromagnetic universe. We explain this on the basis of our solution (Halilsoy and Al-Badawi in Class Quantum Grav 12:3013, 1995), which represents the non-linear superposition of the Schwarzschild solution and the generalized Bertotti–Robinson solution. 相似文献
13.
Various aspects of the C-metric representing two rotating charged black holes accelerated in opposite directions are summarized
and its limits are considered. A particular attention is paid to the special-relativistic limit in which the electromagnetic
field becomes the “magic field” of two oppositely accelerated rotating charged relativistic discs. When the acceleration vanishes
the usual electromagnetic magic field of the Kerr–Newman black hole with gravitational constant set to zero arises. Properties
of the accelerated discs and the fields produced are studied and illustrated graphically. The charges at the rim of the accelerated
discs move along spiral trajectories with the speed of light. If the magic field has some deeper connection with the field
of the Dirac electron, as is sometimes conjectured because of the same gyromagnetic ratio, the “accelerating magic field”
represents the electromagnetic field of a uniformly accelerated spinning electron. It generalizes the classical Born’s solution
for two uniformly accelerated monopole charges. 相似文献
14.
R. Kaya 《General Relativity and Gravitation》2007,39(2):211-221
We study the effect of an external magnetic field on the stability of circular motion around a five dimensional Myers–Perry
metric. Using the Hamilton–Jacobi formalism we derive the effective potential for the radial motion of charged particles around
a five dimensional rotating black hole in a uniform magnetic field. We show that there are stable circular orbits around a
five dimensional rotating black hole immersed in a uniform magnetic field. 相似文献
15.
Hossein Ghaffarnejad 《General Relativity and Gravitation》2008,40(10):2229-2239
Using some suitable combinations of a dynamical unit time-like four-velocity of a preferred reference frame, Ricci tensor
and covariant derivatives of the Brans–Dicke (BD) scalar field, we propose a new scalar–vector–tensor gravity model in which
an Euclidean Jordan–Brans–Dicke (JBD) action is reduced to its Lorentzian version with no used complex coordinates. Thus it
should be play an important role in the process of metric signature transition of a suitable dynamical curved space-time.
In this work we follow the ideas proposed by Barbero et al. As an application of the model, we study a classical perfect fluid
cosmological universe described in a flat Robertson–Walker background metric. Mathematical derivations of the equations predict
a non-singular scale factor for the space-time in the both of dust and radiation dominated states where value of the Brans–Dicke
parameter is fixed, but there is still an arbitrary parameter which should be determined by the boundary values of the cosmological
system. Furthermore its classical cosmological vacuum solutions is obtained as a non-singular model with a fixed Brans–Dicke
parameter. Although there is obtained a singular perfect fluid cosmological solution which may not be suitable, because in
this case the Brans–Dicke parameter is not still fixed. 相似文献
16.
We find the existence of a quantum thermal effect, “Hawking absorption.” near the inner horizon of the Kerr–Newman black hole. Redefining the entropy, temperature, angular velocity, and electric potential of the black hole, we give a new formulation of the Bekenstein–Smarr formula. The redefined entropy vanishes for absolute zero temperature of the black hole and hence it is interpreted as the Planck absolute entropy of the KN black hole. 相似文献
17.
The density distribution of ultracold two-component fermionic gases 6Li, which are confined in a gradient magnetic field and a symmetrical double-well potential, is investigated by employing local-density approximation. It is found that three different regimes including quasi-molecular Bose-Einstein condensation (BECm), the dimers in the unitarity limit (ULd), and Bardeen-Cooper-Schrieffer superfluid (BCS) can coexist at the same time. Furthermore, the ranges of these regimes can be controlled to some extent by tuning the gradient of the magnetic field and the parameters characterizing the properties of the double-well potential. This study is of guidance and significance for experimentally realizing the coexistence of BECm, ULd, and BCS in the double-well potential. 相似文献
18.
Monochromatic, circularly polarized radiation brings useful information on orientations of hyperfine fields in investigation
of magnetic materials. This information can be extracted even from poorly resolved spectra by a model free method. In particular,
the z-component of the average hyperfine magnetic field is given simply by a “center of gravity” of the difference between
the spectra measured with two opposite polarizations. The efficiency of such an approach is demonstrated on the example of
the 57Fe h.m.f. in bcc Cr–Fe–Mn alloys.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
19.
Kjell Rosquist 《General Relativity and Gravitation》2009,41(11):2619-2632
A new unified metric form is presented for the Kerr–Newman geometry. The new form is a generalization of the Boyer–Lindquist
metric involving an arbitrary gauge function of the spheroidal radial variable. Each choice of the gauge function corresponds
to a coordinate system including four of the most important coordinate systems for Kerr–Newman (Boyer–Lindquist, Kerr, Kerr–Schild
and Doran coordinates). The representation is given in terms of a single Minkowski frame together with the gauge function.
This Minkowski frame arises by boosting a static orthonormal frame which is adapted to spheroidal coordinates. Properties
of the boost reflect the rotating nature of the Kerr–Newman solution including an identification of the angular velocities
of the disk and the horizon matching previously known values obtained in other ways. 相似文献
20.
İbrahim Semiz 《General Relativity and Gravitation》2011,43(3):833-846
We construct a gedanken experiment, in which a weak wave packet of the complex massive scalar field interacts with a four-parameter
(mass, angular momentum, electric and magnetic charges) Kerr–Newman black hole. We show that this interaction cannot convert
an extreme the black hole into a naked sigularity for any black hole parameters and any generic wave packet configuration.
The analysis therefore provides support for the weak cosmic censorship conjecture. 相似文献