The quantum nonthermal radiation and horizon surface gravity of an arbitrarily accelerating black hole with electric charge and magnetic charge

Using a new tortoise coordinate transformation,we discuss the quantum nonthermal radiation characteristics near an event horizon by studying the Hamilton-Jacobi equation of a scalar particle in curved space-time,and obtain the event horizon surface gravity and the Hawking temperature on that event horizon.The results show that there is a crossing of particle energy near the event horizon.We derive the maximum overlap of the positive and negative energy levels.It is also found that the Hawking temperature of a black hole depends not only on the time,but also on the angle.There is a problem of dimension in the usual tortoise coordinate,so the present results obtained by using a correct-dimension new tortoise coordinate transformation may be more reasonable.

Hawking radiation from the charged and magnetized BTZ black hole via covariant anomaly

This paper discusses Hawking radiation from the charged and magnetized Bafiados-Teitelboim-Zanelli （BTZ） black hole from the viewpoint of anomaly, initiated by Robinson and Wilczek recently. It reconstructs the electromagnetic field tensor and the Lagrangian of the field corresponding to the source with electric and magnetic charges to redefine an equivalent charge and gauge potential. It employs the covariant anomaly cancellation method to determine the compensating fluxes of charge flow and energy-momentum tensor, which are shown to match with those of the 2- dimensional blackbody radiation at the Hawking temperature exactly.

Dirac Particles' Tunneling Radiation from Dilaton Space-time with Squashed Horizons

The aim of this paper is to investigate Hawking radiation of Dirac particles from the Dilaton space-time with squashed horizons by improving the method of Kerner and Man’s tunneling analysis.We construct appropriate matrices for general covariant Dirac equation,and derive the tunneling probability and Hawking temperature.The results show that both Dirac particles and scalar particles radiate at the same Hawking temperature.

Tunneling of Dirac Particles from Kaluza-Klein Black Hole

Applying the fermions tunneling method, proposed by Kerner and Mann recently, we discuss the tunneling characteristics of Dirac particles from the stationary Kaluza-Klein black hole. To choose Gamma matrix conveniently and avoid the ergosphere dragging effect, we perform it in the dragging coordinate frame. The result shows that Hawking temperature in this case also can be reproduced by the general Dirac equation.

Hawking radiation from a Vaidya black hole by Hamilton-Jacobi method

Using the Hamilton Jacobi method, Hawking radiation from the apparent horizon of a dynamical Vaidya black hole is calculated. The black hole thermodynamics can be built successfully on the apparent horizon. If a relativistic perturbation is given to the apparent horizon, a similar calculation can also lead to a purely thermal spectrum, which corresponds to a modified temperature from the former. The first law of thermodynamics can also be constructed successfully at a new supersurface which has a small deviation from the apparent horizon. When the event horizon is thought as such a deviation from the apparent horizon, the expressions of the characteristic position and temperature are consistent with the previous result that asserts that thermodynamics should be built on the event horizon. It is concluded that the thermodynamics should be constructed on the apparent horizon exactly while the event horizon thermodynamics is just one of the perturbations near the apparent horizon.

A new method of researching fermion tunneling from the Vaidya-Bonner de Sitter black hole

Using the general tortoise coordinate transformation, we research the fermion tunneling of the Vaidya-Bonner de Sitter black hole via a semi-classical method and finally obtain the right surface gravity, Hawking temperature and tunneling rate near the event horizon and cosmical horizon.

Charged Fermions Tunneling from a Rotating Charged Black Hole in 5-Dimensional Gauged Supergravity

Recent research shows that Hawking radiation from black hole horizon can be treated as a quantum tunneling process, and fermions tunneling method can successfully recover Hawking temperature. In this tunneling framework, choosing a set of appropriate matrices γ^μ is an important technique for fermions tunneling method. In this paper, motivated by Kerner and Man＇s fermions tunneling method of 4 dimension black holes, we further improve the analysis to investigate Hawking tunneling radiation from a rotating charged black hole in 5-dimensional gauged supergravity by constructing a set of appropriate matrices γ^μ for general covariant Dirac equation. Finally, the expected Hawking temperature of the black hole is correctly recovered, which takes the same form as that obtained by other methods. This method is universal, and can also be directly extend to the other different-type 5-dimensional charged black holes.

Hawking Radiation of Grumiller Black Hole

In this paper, we consider the relativistic Harnilton-Jacobi （HJ） equation and study Hawking radiation （HR） of scalar particles from uncharged Grumiller black hole （GBH） which is affordable for testing in astrophysics. It is a/so known as Rindler modified Schwarzschild BH. Our aim is not only to investigate the effect of the Rindler parameter a on the Hawking temperature （TH ）, but to examine whether there is any discrepancy between the computed horizon temperature and the standard TH as well. For this purpose, in addition to its naive coordinate system, we study on the three regular coordinate systems, which are Painlevd--Gullstrand （PG）, ingoing Edding^on-Finkelstein （IEF）, and Kruskal-Szekeres （KS） coordinates. In o21 coordinate systems, we calculate the tunneling probabilities of incoming and outgoing scalar particles from the event horizon by using the HJ equation. It has been shown in detail that the considered HJ method is concluded with the conventional T~ in all these coordinate systems without giving rise to the famous factor-2 problem. Filrthermore, in the PG coordinates Parikh-Wilczek＇s tunneling （PWT） method is employed in order to show how one can integrate the quantum gravity （QG） corrections to the semiclassical tunneling rate by including the effects of self-gravitation and back reaction. We then show how this yields a modification in the TH.

Tunnelling effect of the non-stationary Kerr black hole

Extending Parikh and Wilczek＇s work to the non-stationary black hole, we study the Hawking radiation of the non-stationary Kerr black hole by the Hamilto-Jacobi method. The result shows that the radiation spectrum is not purely thermal and the tunnelling probability is related to the change of Bekenstein Hawking entropy, which gives a correction to the Hawking thermal radiation of the black hole.

What Connects Dark Matter and Black Holes?

Dark matter is a major component of the universe, about six times more abundant than ordinary visible matter. We measure the effects of its mass, but it escapes the telescopes. It has the particularity of emitting no radiation and interacting only by the action of gravity. The main purpose of this article is to try to answer what dark matter is: we conjecture that it is composed of magnetically charged neutrinos, true magnetic monopoles. But that requires a huge conceptual leap: Maxwell’s laws must be inverted and the electric charge becomes a magnetic charge. Asymmetric “reversed” Maxwell’s laws would provide the “dark” magnetic charge that would replace the electric charge. The very form of the Dirac equation, which imposed on ordinary matter that the particle carries an electric charge and obeys the principal properties of the electron, would impose in the dark matter that the “dark” particle obeys the main properties of a neutrino associated with a magnetic charge. The second aim of the article is to show that dark matter is derived from black holes, mainly from active supermassive black holes. This requires a second conceptual leap: the horizon of the black hole undergoes a high temperature and an intense pressure of magnetic fields which cause a blackout and a phase transition (or broken symmetry) when the matter crosses the horizon. The result is a reversal of Maxwell’s laws: a magnetic charge is substituted for the electric charge, and the electric current becomes a tributary of the magnetic current. A third important conceptual leap follows: sterile magnetic neutrinos created inside the black hole would cross the horizon to the outside to constitute dark matter.

Analytic solutions in the acoustic black hole analogue of the conical Kerr metric

We study the sound perturbation of a rotating acoustic black hole in the presence of a disclination. The radial part of the massless Klein-Gordon equation is written into a Heun form, and its analytical solution is obtained. These solutions have an explicit dependence on the parameter of the disclination. We obtain the exact Hawking-Unruh radiation spectrum.

Quantum nonthermal effect of the Vaidya-Bonner-de Sitter black hole

Using the Hamilton-Jacobi equation of a scalar particle in the curve space-time and a correct- dimension new tortoise coordinate transformation, the quantum nonthermal radiation of the Vaidya-Bonner-de Sitter black hole is investigated. The energy condition for the occurrence of the Starobinsky-Unruh process is obtained. The event horizon surface gravity and the Hawking temperature on the event horizon are also given.

Quantum tunnelling radiation from static and rotating black lenses in five dimensions

Black lenses with L(n,1) horizon topology in five dimensions have many unusual properties shared by neither Myers-Perry black holes with event-horizon topology S 3,nor 5-dimensional black rings with event-horizon topology S 2 × S 1.In this work,by constructing appropriate matrices γμ for the general covariant Dirac equation,we further extend the fermion tunnelling method to 5-dimensional static and rotating black lenses.As a result,it is interesting to find as in black hole cases,fermions tunnelling can also result in correct Hawking temperatures for the static and rotating black lenses.

A NEW APPROACH FOR DISCUSSING BACK-REACTION OF BLACK HOLES

The temperature of evaporating black holes is usually calculated with a two-dimensional model with the back-reaction effects considered. The following relation which is valid in a static or a stationary space-time is generalized to a non-static and non-stationary

动态Dilaton-Maxwell时空中Dirac场的熵

从求解Dilaton-Maxwell时空中Dirac粒子所遵从的动力学方程出发,计算出该时空中Dirac场的熵,得到了熵与视界的面积成正比的结论.

用旋量零标架方法导出带电Schwarzschild黑洞时空中Dirac粒子的能级

用旋量零标架方法对带电Schwarzschild黑洞 (Reissner Nordstrom)时空中旋量粒子的Dirac方程分离变量 ,并退耦为普通微分方程组 ,从所获得的径向方程和角向方程出发进一步导出了Dirac粒子的能级方程 .

动态球对称黑洞中Dirac粒子的Hawking辐射

在动态球对称黑洞时空中求解狄拉克方程,采用了Tortoise坐标变换将狄拉克方程变成Tortoise坐标下的形式,在视界面附近化成了标准的波动方程,得到在视界面附近狄拉克粒子的Hawking辐射温度,成功地导出了Hawking热谱公式.该谱由黑洞的度规分量g00和g01决定.

含整体单极动态黑洞Dirac粒子的热辐射

作者通过构造对称化的零标架,并计算Ricci旋系数,导出了含整体单极动态黑洞时空中粒子的Dirac方程,然后引入广义乌龟坐标变换,使Dirac方程在视界面上退耦,并利用Damour-Ruffini方法,得到了含整体单极动态黑洞时空中粒子的Hawking温度和热辐射谱.

一类稳态轴对称非Kerr黑洞视界附近的Dirac能级

研究了一类具有质量多极矩的稳态轴对称非Ｋｅｒｒ黑洞视界附近的Ｄｉｒａｃ能级．用计算机绘制了几种能级图形．能级的形态不同于Ｋｅｒｒ黑洞和史瓦西黑洞，显示了这类非Ｋｅｒｒ黑洞的自旋和质量多极矩的影响．

Vaidya-Bonner黑洞周围时空中Dirac粒子的量子能级

从Vaidya-Bonner黑洞周围时空中旋量粒子的Dirac方程经分离变量并退耦后的径向方程和角向方程出发,导出了Dirac粒子的能级方程.得到了粒子的能量分布不仅与粒子的质量、电荷、自旋量子数、角量子数、磁量子数有关,还与黑洞周围的时空结构及视界变化有关.给出了Vaidya-Bonner黑洞自发辐射Dirac粒子的能量条件.