共查询到20条相似文献,搜索用时 31 毫秒
1.
Particle production in curved spacetime has been discussed through the method of complex time WKB approximation. We consider
Dirac equation in non-flat spacetime to understand particle production as particle-antiparticle rotation. The method is also
generalized to understand particle production through parametric resonance. To understand the method of CWKB we consider particle
production in Kasner spacetime as an example. 相似文献
2.
We study the behaviour of Dirac current in expanding spacetime with Schrödinger and de Sitter form for the evolution of the scale-factor. The study is made to understand the particle-antiparticle rotation and the evolution of quantum vacuum leading to particle production in such spacetime. 相似文献
3.
This paper investigates the quantum Dirac field in n+1-dimensional flat
spacetime and derives a lower bound in the form of quantum
inequality on the energy density averaged
against spacetime sampling functions. The state-independent quantum inequality
derived in the present paper is
similar to the temporal quantum energy inequality and
it is stronger for massive
field than for massless one. It also
presents the concrete results of the quantum inequality in 2 and
4-dimensional spacetimes. 相似文献
4.
We investigate the creation rate of massive spin-1 bosons in the de Sitter universe by a time-dependent electric field via the Duffin–Kemmer–Petiau (DKP) equation. Complete solutions are given by the Whittaker functions and particle creation rate is computed by using the Bogoliubov transformation technique. We analyze the influence of the electric field on the particle creation rate for the strong and vanishing electric fields. We show that the electric field amplifies the creation rate of charged, massive spin-1 particles. This effect is analyzed by considering similar calculations performed for scalar and spin-1/2 particles. 相似文献
5.
In this work a number of examples are used to illustrate uniqueness of physical prediction of the Dirac theory in a curved and a flat spacetime. Dirac Hamiltonians in arbitrary, including time‐dependent, gravitational fields uniquely determine physical characteristics of quantum‐mechanical systems irrespective of the choice of the tetrad fields. Direct spin‐rotation coupling that occurs with a certain choice of tetrads does not manifest itself in final physical characteristics of the systems and therefore does not represent a physically relevant effect. 相似文献
6.
Shahpoor Moradi 《International Journal of Theoretical Physics》2009,48(4):969-980
The exact solutions of the Dirac equation are discussed for a Robertson-Walker spacetime with asymptotically Minkowskian in and out regions. We obtain the mode solutions which reduce to positive and negative Minkowskian spinors in asymptotically regions.
Using the obtained solutions we compute the density of created particles. 相似文献
7.
8.
We consider the teleportation in the background of Kerr-Newman spacetime. Because of the Hawking effect, the fidelity of the teleportation is reduced. The results also show the fidelity is closely related to the mass, charge and rotating velocity of the black hole: high fidelity can be reached for massive, slowly rotating Kerr-Newman black holes. 相似文献
9.
10.
The stability problem of the Rindler spacetime is carefully
studies by using the scalar wave perturbation. Using two different
coordinate systems, the scalar wave equation is investigated. The
results are different in the two cases. They are analysed and
compared with each other in detail. The following conclusions are
obtained: (a) the Rindler spacetime as a whole is not stable; (b) the
Rindler spacetime can exist stably only as part of the Minkowski
spacetime, and the Minkowski spacetime can be a real entity
independently; (c) there are some defects for the scalar wave
equation written by the Rindler coordinates, and it is unsuitable for
the investigation of the stability properties of the Rindler
spacetime. All these results may shed some light on the stability
properties of the Schwarzschild black hole. It is natural and
reasonable for one to infer that: (a) perhaps the Regge--Wheeler
equation is not sufficient to determine
the stable properties; (b) the Schwarzschild black hole as a whole
might be really unstable; (c) the Kruskal spacetime is stable and can
exist as a real physical entity; whereas the Schwarzschild black hole
can occur only as part of the Kruskal spacetime. 相似文献
11.
12.
Some properties related to the NUT--Taub-like spacetime,
such as the surface of infinite red-shift, horizon, singularity
and the area of the NUT--Taub-like black hole are discussed.
Furthermore, the geodesics in the NUT--Taub-like spacetime are
obtained in some special cases. Specifically, the circular orbits
for a massive particle are derived, which can reduce to the cases
of the Schwarzschild spacetime and the NUT--Taub spacetime when
m*=0 and m*\ll M, respectively. 相似文献
13.
Howard E. Brandt 《Foundations of Physics Letters》1992,5(1):43-55
The maximum possible proper acceleration relative to the vacuum determines much of the differential geometric structure of the space-time tangent bundle. By working in an anholonomic basis adapted to the spacetime affine connection, one derives a useful expression for the Riemann curvature scalar of the bundle manifold. The explicit documentation of the proof is important because of the central role of the curvature scalar in the formulation of an action with resulting field equations and associated solutions to physical problems. 相似文献
14.
Howard E. Brandt 《Foundations of Physics Letters》1993,6(3):245-255
It is demonstrated that the spacetime tangent bundle, in the case of a Finsler spacetime, is complex, provided that the gauge curvature field vanishes. This is accomplished by determining the conditions for the vanishing of the Nijenhuis tensor in the anholonomic frame adapted to the spacetime connection. 相似文献
15.
In this paper we classified the matter collineations (MCs) of Bianchi type II spacetime according to the degenerate and non-degenerate energy-momentum tensor. It is shown that when the energy-momentum tensor is degenerate, most of the cases yield infinite dimensional MCs whereas some cases give finite dimensional Lie algebras in which there are three, four or five MCs. For the non-degenerate matter tensor cases we obtained that the Lie algebra of MCs is finite dimensional, in which the number of MCs are also three, four or five. Furthermore, we discussed the physical implications of the obtained MCs in the case of perfect fluid as source. 相似文献
16.
We extend to higher dimensions an earlier work of Santos regarding junction conditions for a spherical fluid distribution
with heat flux and an electromagnetic field. It is observed that the pressure at the surface of distribution does not vanish
when the heat flow is present. 相似文献
17.
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
18.
The interference phase of the high energy mass neutrinos and the low energy thermal neutrons in a gravitational field are studied. For the mass neutrinos, we obtain that the phase calculated along the null is equivalent to the half phase along the geodesic in the high energy limit, which means that the correct relative phase of the mass neutrinos is either the null phase or the half geodesic phase. Further we point out the importance of the energy condition in calculating the mass neutrino interference phase. Moreover, we apply the covariant phase to the calculation of the thermal neutron interference phase, and obtain the consistent result with that exploited in COW experiment. 相似文献
19.
利用Wentzel-Kramers-Brillouin近似计算了Taub-NUT时空事件视界附近自旋为1/2,1,3/2,2等无质量场的熵密度、压强和能量密度.结果表明,自旋场附近的热力学量不仅具有与平直时空相同的主导项,还多了两项自旋依赖的附加项.
关键词:
Taub-NUT时空
自旋场
热力学量 相似文献
20.
由尘埃物质粒子的集合来形成一个理想的离散时空的Friedmann宇宙模型并证明了它是奇性 自由的.
关键词:
离散时空
尘埃物质
Friedmann宇宙
奇性自由 相似文献