The energy of Einstein-Maxwell dilation-axion black hole in the teleparallel geometry

The energy of the stationary axisymmetric Einstein-Maxwell dilation-axion （EMDA） black hole is studied in the context of the Hamiltonian formulation of the teleparallel equivalence of general relativity （TEGR）. The energy expression for the finite and arbitrary space-like two spheres is exactly computed by means of the integral form of the constraint equations of the formalism naturally without any restriction on the metric parameters. We also show that our results give the same values obtained by other methods for some special cases.     

稳态轴对称爱因斯坦—麦克斯韦伸缩子黑洞时空中标量场的晚期拖尾

稳态轴对称爱因斯坦—麦克斯韦伸缩子黑洞时空中无质量和有质量标量场的晚期拖尾将被解析地研究. 研究表明: 无质量扰动的渐近行为被负幂率衰减拖尾主导, 而有质量扰动的中期渐近行为被振荡负幂率衰减拖尾主导.     

Newtonian Forms for Dilaton Spacetimes in String Theory

We show that the Newtonian forms for the motion of particles in mechanics and for light in geometrical optics can be extend to the Gibbons-Meada and the GarfinMe-Horne dilaton spacetimes in string theory. As an example,we study the bending of the light rays, the perihelion advance of planet, and the radar echo delay in the dilaton spacetimes. The results show that the gravitational effects arising from the dilaton can be observed provided that the dilaton is large enough.     

地球引力背景下的卫星-地面量子时钟同步

正原子钟是迄今为止人类能制造的最精密的设备,精确的定时和授时在导航、卫星定位、相对论效应的实验检测、引力波的探测等多个系统或科学计划中扮演了重要的角色。时钟同步事实上是一个比较经典的课题。对于这一问题,人们最熟悉的是两个经典时钟同步方案:爱因斯坦时钟同步方案和爱丁顿的慢钟搬运方案。现有的卫星定位系统的时钟同步用的是前者,人们利用激光或其他信息载     

STATISTICAL ENTROPIES OF THE TAUB－NUT/BOLT AdS SPACES FROM THE HORIZON CONFORMAL FIELD THEORY

The covariant phase technique is used to compute the constraint algebra of the four-dimensional space-times which are asymptotic to anti-de Sitter (AdS), such as the planar Taub－NUT AdS and Taub－bolt AdS spaces, and the hyperbolic Taub－bolt AdS space. The standard Virasoro subalgebrae with corresponding central charges for these objects are constructed and the resulting densities of states yield the expected Bekenstein－Hawking entropies.     

无切的具有电磁场共形Ricci—平理想流体时空

本文从共形Ricci-平条件出发,导出了具有电磁场理想流体Einstein-Maxwell方程的Newman-Penrose形式,并求出了在无切条件下电磁场为0和状态方程为P=(γ-1)ω时方程的严格解,文[1]的结果是本文的一个特例。     

Dirac Quasinormal Modes of the Schwarzschild-anti-de Sitter Black Hole with a Global Monopole

The quasinormal modes associated with the decay of Dirac field perturbation around a Schwarzschild-anti-de Sitter black hole with a global monopole （SAdSBHGM） are calculated using the Horowitz-Hubeny approach. For the large SAdSBHGM, we find that η has little effect on the quaslnormal frequencies. However, for the intermediate and small SAdSBHGM, in the limit η→1/√8π, the real parts of the fundamental quasinormal frequencies approximate the linear functions of Tand the imaginary ones approximate the linear functions of r＋.     

Asymptotic Tails of Massive Scalar Fields in a Stationary Axisymmetric EMDA Black Hole Geometry

The late-time tail behaviour of massive scalar fields is studied analytically in a stationary axisymmetric EinsteinMaxwell Dilaton-Axion (EMDA) black hole geometry. It is shown that the asymptotic behaviour of massive perturbations is dominated by the oscillatory inverse power-law decaying tail t^-(l 3/2) sin(μt) at the intermediate late times, and by the asymptotic tail t^-5/6 sin(μt) at asymptotically late times, with μ being field mass. Our result seems to suggest that the intermediate tails t^-(l 3/2) sin(μt) and the asymptotically tails t^-5/6 sin(μt) maybe a quite general feature for evolution of massive scalar fields in any four-dimensional asymptotically fiat rotating black hole backgrounds.     

THERMODYNAMICS OF GLOBAL MONOPOLE ANTI-DE-SITTER BLACK HOLE IN GRAND CANONICAL ENSEMBLE

In this paper, we investigate the thermodynamics of the global monopole anti-de-Sitter black hole in the grand canonical ensemble following the York's formalism. The black hole is enclosed in a cavity with a finite radius where the temperature and potential are fixed. We have studied some thermodynamical properties, i.e. the reduced action, thermal energy and entropy. By investigating the stability of the solutions, we find stable solutions and instantons.     

Quantum Spectrum of Stationary Axisymmetric Einstein-Maxwell Dilaton-Axion Black Hole

The horizon area spectrum of a stationary axisymmetric Einstein-Maxwell Dilaton-Axion （EMDA） black hole is studied by using Gour-Medved＇s method. It is found that the quantized area operator can be expressed in terms of two quantum numbers, i.e. A = 8πh（1/2 ＋n ＋ ι）, where n and ι are strictly non-negative integers and related respectively to the mass and angular momentum. The result shows that there is qualitatively a property difference between the quantum spectrum of the EMDA black hole which obtained from string theory and the one of the Kerr-Newman black hole which obtained from general relativity, although both they are characterized by mass, angular momentum and charge.