共查询到20条相似文献,搜索用时 31 毫秒
1.
A. López-Ortega 《General Relativity and Gravitation》2006,38(11):1565-1591
We calculate the exact values of the quasinormal frequencies for an electromagnetic field and a gravitational perturbation
moving in D-dimensional de Sitter spacetime (D ≥ 4). We also study the quasinormal modes of a real massive scalar field and compare our results with those of other references. 相似文献
2.
A. López-Ortega 《General Relativity and Gravitation》2007,39(7):1011-1029
We find exact solutions to the Dirac equation in D-dimensional de Sitter spacetime. Using these solutions we analytically calculate the de Sitter quasinormal (QN) frequencies
of the Dirac field. For the massive Dirac field this computation is similar to that previously published for massive fields
of half-integer spin moving in four dimensions. However to calculate the QN frequencies of the massless Dirac field we must
use distinct methods in odd and even dimensions, therefore the computation is different from that already known for other
massless fields of integer spin. 相似文献
3.
S. Mignemi 《Annalen der Physik》2010,522(12):924-940
We discuss the generalization of Doubly Special Relativity to a curved de Sitter background. The model has three fundamental observer‐independent scales, the velocity of light c, the de Sitter radius α, and the Planck energy κ, and can be realized through a nonlinear action of the de Sitter group on a noncommutative position space. We consider different choices of coordinates on the de Sitter hyperboloid that, although equivalent, may be more suitable for treating different problems. Also the momentum space can be described as a hyperboloid embedded in a five‐dimensional space, but in this case different choices of coordinates lead to inequivalent models. We investigate the kinematics and the Hamiltonian dynamics of some specific models and describe some of their phenomenological consequences. Finally, we show that it is possible to construct a model exhibiting a duality for the interchange of positions and momenta together with the interchange of α and κ. 相似文献
4.
The quantum entropies due to the scalar and Dirac fields are investigated in a pure de Sitter spacetime. The leading divergent terms in both cases are regularized by the Pauli-Villars scheme. It is shown that the explosive entropies can be renormalized according to the Bekenstein-Hawking formula. 相似文献
5.
A. López-Ortega 《General Relativity and Gravitation》2008,40(7):1379-1401
By using the sixth order WKB approximation we calculate for an electromagnetic field propagating in D-dimensional Schwarzschild and Schwarzschild de Sitter (SdS) black holes its quasinormal (QN) frequencies for the fundamental
mode and first overtones. We study the dependence of these QN frequencies on the value of the cosmological constant and the
spacetime dimension. We also compare with the results for the gravitational perturbations propagating in the same background.
Moreover we compute exactly the QN frequencies of the electromagnetic field propagating in D-dimensional massless topological black hole and for the charged D-dimensional Nariai spacetime we calculate exactly the QN frequencies of the coupled electromagnetic and gravitational perturbations. 相似文献
6.
In the framework of open quantum systems, we study the internal dynamics of both freely falling and static two-level atoms interacting with quantized conformally coupled massless scalar field in de Sitter spacetime. We find that the atomic transition rates depend on both the nature of de Sitter spacetime and the motion of atoms, interestingly the steady states for both cases are always driven to being purely thermal, regardless of the atomic initial states. This thermalization phenomenon is structurally similar to what happens to an elementary quantum system immersed in a thermal field, and thus reveals the thermal nature of de Sitter spacetime. Besides, we find that the thermal baths will drive the entanglement shared by the freely falling atom (the static atom) and its auxiliary partner, a same two-level atom which is isolated from external fields, to being sudden death, and the proper time for the entanglement to be extinguished is computed. We also analyze that such thermalization and disentanglement phenomena, in principle, could be understood from the perspective of table-top simulation experiment. 相似文献
7.
A. López-Ortega 《General Relativity and Gravitation》2006,38(12):1747-1770
Using the monodromy method we calculate the asymptotic quasinormal frequencies of an electromagnetic field moving in D-dimensional Schwarzschild and Schwarzschild de Sitter black holes (D ≥ 4). For the D-dimensional Schwarzschild anti-de Sitter black hole we also compute these frequencies with a similar method. Moreover, we calculate the electromagnetic normal modes of the D-dimensional anti-de Sitter spacetime. 相似文献
8.
Analytical Solutions of the Gravitational Field Equations in de Sitter and Anti-de Sitter Spacetimes
The generalized Laplace partial differential equation, describing gravitational fields, is investigated in de Sitter spacetime from several metric approaches—such as the Riemann, Beltrami, Börner-Dürr, and Prasad metrics—and analytical solutions of the derived Riccati radial differential equations are explicitly obtained. All angular differential equations trivially have solutions given by the spherical harmonics and all radial differential equations can be written as Riccati ordinary differential equations, which analytical solutions involve hypergeometric and Bessel functions. In particular, the radial differential equations predict the behavior of the gravitational field in de Sitter and anti-de Sitter spacetimes, and can shed new light on the investigations of quasinormal modes of perturbations of electromagnetic and gravitational fields in black hole neighborhood. The discussion concerning the geometry of de Sitter and anti-de Sitter spacetimes is not complete without mentioning how the wave equation behaves on such a background. It will prove convenient to begin with a discussion of the Laplace equation on hyperbolic space, partly since this is of interest in itself and also because the wave equation can be investigated by means of an analytic continuation from the hyperbolic space. We also solve the Laplace equation associated to the Prasad metric. After introducing the so called internal and external spaces—corresponding to the symmetry groups SO(3,2) and SO(4,1) respectively—we show that both radial differential equations can be led to Riccati ordinary differential equations, which solutions are given in terms of associated Legendre functions. For the Prasad metric with the radius of the universe independent of the parametrization, the internal and external metrics are shown to be of AdS-Schwarzschild-like type, and also the radial field equations arising are shown to be equivalent to Riccati equations whose solutions can be written in terms of generalized Laguerre polynomials and hypergeometric confluent functions. 相似文献
9.
There is an apparent discrepancy in the literature with regard to the quasinormal-mode frequencies of Schwarzschild–de Sitter
black holes in the degenerate-horizon limit. On the one hand, a Poschl–Teller-inspired method predicts that the real part
of the frequencies will depend strongly on the orbital angular momentum of the perturbation field whereas, on the other hand,
the degenerate limit of a monodromy-based calculation suggests there should be no such dependence (at least, for the highly
damped modes). In the current paper, we provide a possible resolution by critically re-assessing the limiting procedure used
in the monodromy analysis. 相似文献
10.
分析了在相对论体系中狭义相对性原理和宇宙学原理之间的关系以及Beltrami-de Sitter -陆启铿疑难.指出可以把狭义相对性原理推广到非零常曲率时空,在具有Beltrami度规 的de Sitter/反de Sitter时空中建立狭义相对论的运动学和粒子动力学. 在这类狭义相对 论中,相对于Beltrami坐标同时性,Beltrami坐标系就是惯性坐标系,相应的观测者为惯 性观测者; 对于自由粒子和光讯号, 惯性定律成立;可以定义可观测量,它们不但守恒而且还 满足推广的爱因斯坦关系.除了Beltrami坐标时同时性之外,对于共动观测, 还可以取固 有时同时性;此时,Beltrami度规成为Robertson-Walker型的度规,其3维空间是闭的,对 于平坦的偏离为宇宙学常数的量级.这表明,在这类狭义相对论中,相对性原理与“完美”宇 宙学原理之间存在内在联系,并不存在那些问题.进而,基于最新观测事实,重述了Mach原 理;指出对于Beltrami-de Sitter/反de Sitter时空,宇宙学常数恰恰给出惯性运动的起 源.
关键词:
狭义相对性原理
宇宙学原理
de Sitter不变的狭义相对论
Beltrami-de Sitter时空
同时性
Mach原理 相似文献
11.
Francisco J. Herranz Angel Ballesteros N. Rossano Bruno 《Czechoslovak Journal of Physics》2004,54(11):1321-1327
We analyze among all possible quantum deformations of the 3+1 (anti)de Sitter algebras, so(3,2) and so(4,1), which have two specific non-deformed or primitive commuting operators: the time translation/energy generator and a rotation. We prove that under these conditions there are only two families of two-parametric (anti)de Sitter Lie bialgebras. All the deformation parameters appearing in the bialgebras are dimensionful ones and they may be related to the Planck length. Some properties conveyed by the corresponding quantum deformations (zero-curvature and non-relativistic limits, space isotropy, . . . ) are studied and their dual (first-order) non-commutative spacetimes are also presented. 相似文献
12.
A. López-Ortega 《General Relativity and Gravitation》2012,44(9):2387-2400
Modifying a method by Horowitz and Hubeny for asymptotically anti-de Sitter black holes, we establish the classical stability of the quasinormal modes of the de Sitter spacetime. Furthermore using a straightforward method we calculate the de Sitter quasinormal frequencies of the gravitational perturbations and discuss some properties of the radial functions of these quasinormal modes. 相似文献
13.
Athanasios Prikas 《General Relativity and Gravitation》2004,36(8):1841-1869
We study q-stars with various symmetries in anti de Sitter spacetime in 3+1 dimensions. Comparing with the case of flat spacetime, we find that the value of the field at the center of the soliton is larger when the other parameters show a more complicated behavior. We also investigate their phase space when the symmetry is local and the effect of the charge to its stability. 相似文献
14.
F. Darabi 《International Journal of Theoretical Physics》2009,48(3):815-824
We revisit the Casimir effect for two concentric spherical shells in de Sitter background with a new geometric configuration,
namely Euclidean signature between and Lorentzian signature outside the spheres with different cosmological constants, for
a massless scalar field satisfying Dirichlet boundary conditions on the spheres. It is shown that an extra constant pressure
emerges due to this signature changing configuration. Some interesting aspects of this extra term are then discussed. 相似文献
15.
16.
A. López-Ortega 《General Relativity and Gravitation》2004,36(6):1299-1319
We show that the Dirac equation is separable in the circularly symmetric metric in three dimensions and when the background spacetime is de Sitter we find exact solutions to the radial equations. Using these results we show that the de Sitter horizon has a cross section equal to zero for the massless Dirac field, as in the case of the scalar field. Also, using the improved brick wall model we calculate the fermionic entropy associated with the de Sitter horizon and we compare it with some results previously published. 相似文献
17.
Haryanto M. Siahaan 《中国物理C(英文版)》2023,47(3):035105-035105-10
We study a charged Taub-NUT spacetime solution in the Dvali-Gabadadze-Porrati (DGP) brane. We show that the Reissner-Nordstrom-Taub-NUT-de Sitter solution of Einstein-Maxwell gravity solves the corresponding equations of motion, where the cosmological constant is related to the cross-over scale in the DGP model. Following the approach by Teitelboim in discussing the thermodynamics of de Sitter spacetime and the proposal by Wu et al. for a conserved charge associated with the NUT parameter, we obtain the generalized Smarr mass formula and the first law of thermodynamics of the spacetime. 相似文献
18.
WANG Bo XU Zhan 《理论物理通讯》2008,49(4):933-940
From a five-dimensional Minkowski view the five-dimensional angular momentum of a free spin-O particle moving in de Sifter spacefime is conservative, by which its fimelike geodesics can be labeled completely and uniquely. Based on that observation and working in Belframi coordinate for de Sifter spacefime, solutions and their asymptotic behavior to the Belframi-de Sifter-Klein-Gordon equation are given. 相似文献
19.
Jaume Garriga Jaume Garriga Ariel Megevand Ariel Megevand 《International Journal of Theoretical Physics》2004,43(3):883-904
Decay of a de Sitter vacuum may proceed through a static instanton, representing pair creation of critical bubbles separated by a distance comparable to the Hubble radius—a process somewhat analogous to thermal activation in flat space. We compare this with related processes recently discussed in the literature. 相似文献
20.
Jia-Feng Chang Juan Huang You-Gen Shen 《International Journal of Theoretical Physics》2007,46(10):2617-2625
Recent research of massive fields quasinormal modes suggested that the arbitrary long living modes can be exist. Using different
orders of WKB method, we study the massive scalar fields quasinormal modes of Schwarzschild–de Sitter black holes. It is shown
that the WKB method can not applied for large massive scalar fields directly in asymptotic flat space-time but can fit well
in de Sitter space-time. We prove the non-existence of QRMs in de Sitter space-time and find that the real parts of QNMs increase
linearly and the imaginary parts approach to special values as the mass of scalar fields increase. 相似文献