六维动态球对称黑洞的量子统计熵

运用在brick-wall方法的基础上发展起来的薄膜模型计算了六维动态黑洞的自由能和玻色子熵，然后应用Г矩阵方法计算了费米子熵．结果显示六维动态黑洞的玻色子熵和费米子熵有相同的形式，它们之间只相差一个系数．并且仍然满足Bekenstein-Hawking的熵与面积的关系．     

缘于任意自旋场的Vaidya黑洞的熵

采用在brick模型基础上发展起来的membrane模型，计算了缘于任意自旋场的非静态黑洞——Vaidya黑洞的自由能和熵。结果表明，玻色子场(自旋s=1，2)和费米子场(自旋s=1／2)的熵都恰好与黑洞的视界面积成正比，这与静态和稳态的情况相同。而且，玻色子和费米子场的熵具有相同的形式，二相差一个系数。     

缘于任意自旋场的Vaidya黑洞的熵(英文)

用在brick模型基础上发展起来的membrane模型 ,计算了缘于任意自旋场的非静态黑洞———Vaidya黑洞的自由能和熵。结果表明 ,玻色子场 (自旋s =1,2 )和费米子场 (自旋s =1/2 )的熵都恰好与黑洞的视界面积成正比 ,这与静态和稳态的情况相同。而且 ,玻色子和费米子场的熵具有相同的形式 ,二者相差一个系数     

2维弦论中的黑洞的熵

在2维弦论黑洞背景时空中求解了具有't Hooft的边界条件和“准周期”边界条件的Klein-Gor-don方程和Dirac方程,分别计算了相应的玻色子熵和费米子熵,发现它们具有同一发散形式,两仅相差一个系数。     

低维动态黑洞的熵

运用在砖墙模型方法的基础上发展起来的薄膜模型计算了1 1维和2 1维动态时空中的黑洞的熵。结果表明在低维动态时空中，黑洞熵仍满足Bekenstein—Hawking熵与面积的关系。     

1＋1维黑洞背景时空中的熵

利用′ｔＨｏｏｆｔ的边界条件和“准周期”边界条件分别求解了１＋１维黑洞背景时空中的ＫｌｅｉｎＧｏｒｄｏｎ方程和Ｄｉｒａｃ方程,并计算了相应的玻色子熵与费米子熵,发现它们具有同一发散形式,两者仅相差一个系数     

自引力辐射体系的熵与引力坍缩

本利用李立新和刘辽导出的黑洞视界附近的辐射态方程，计算了约束在一个球形盒子中的自引力辐射体系的熵（不含中心黑洞和含有中心黑洞两种情况）。与Ｓｏｒｋｉｎ等人的计算比较，本的结果不会出现发散困难，而且体系的总熵（包括中心黑洞的熵）的上限正好等于坍缩后形成的同质量的黑洞熵。作认为，自引力辐射体系坍缩的合理模式是先形成中心黑洞，然后中心黑洞逐渐长大直至整个体系全部坍缩为黑洞。在坍缩过程中，任一中间态     

自引力辐射体系的熵与引力坍缩

本文利用李立新和刘辽导出的黑洞视界附近的辐射态方程，计算了约束在一个球形盒子中的目引力辐射体系的墙（不含中心黑洞和含有中心黑洞两种情况）．与Sorkin等人的计算比较，本文的结果不会出现发散困难，而且体系的总摘（包括中心黑洞的墙）的上阳正好等于坍缩后形成的同质量的黑洞嫡．作者认为，自引力辐射体系坍绩的合理模式是先形成中心黑洞，然后中心黑洞逐渐长大直至整个体系全部坍缩为黑洞．在坍缩过程中，任一中间态的媳总是比末态的黑洞墙小，到坍缩过程结束总熵才等于对应的黑洞摘．这一结果为黑洞滴的起源提供了一个合理的解释．     

低维动态黑洞的熵

运用在砖墙模型方法的基础上发展起来的薄膜模型计算了 1 1维和 2 1维动态时空中的黑洞的熵。结果表明在低维动态时空中 ,黑洞熵仍满足Bekenstein -Hawking熵与面积的关系     

EGUP与黑洞熵的修正值

目前,人们对黑洞Bekenstein-Hawking熵的量子修正值产生了极大的兴趣,尤其是黑洞熵对数修正项的系数.在广义不确定关系(GUP)的基础上,通过引入了推广的广义不确定关系(EGUP),运用面积定理计算了3类时空的黑洞熵的修正值,得到的黑洞熵的修正项的系数是正的.这种计算方法不仅对单视界时空适用,而且对有内视界的黑洞时空依然成立,并且在EGUP基础上计算出黑洞熵的修正值.相比GUP基础上得到的黑洞熵,EGUP可以应用于大尺度时空下,所以应用范围更广.此计算方法简洁明了,物理意义明确,可为黑洞熵对数修正值系数的确定提供参考.     

Spacetime dimensionality and logarithmic prefactor in the black hole entropy relation

We study the relation between the existence of the logarithmic prefactor and spacetime dimensionality in black hole entropy relation by a detailed study of a TeV-scale black hole entropy. In a model universe with large extra dimensions and within the Generalized Uncertainty Principle (GUP) framework, we show that probability of black hole production in the Large Hadronic Collider (LHC) decreases for sufficiently large values of the GUP parameter. In this regard, even observation of micro-black holes may be suppressed at TeV energy scale. We determine also the GUP parameter in an extra dimensional scenario by comparing black hole entropy calculated within the GUP and loop quantum gravity frameworks.     

Extremal black hole entropy satisfying the Nernst theorem

Quantum entropy of extremal black holes has been discussed by many authors. However the contribution of inner event horizon has not been considered. In this paper, we consider the Reissner-Nordström-anti-de Sitter black hole, and show that the contributions lead extremal black hole entropy to obey the Nernst theorem, naturally. Therefore the contributions are important and cannot be neglected in near-extremal and extremal black hole cases.     

Change in entropy of non-spinning black holes w.r.t. the radius of event horizon in XRBs

The present research paper discusses the derivation for the change in entropy of Non- spinning black holes with respect to the change in the radius of event horizon applying the first law of black hole mechanics ( $\delta M = \frac{\kappa}{8\pi} \delta A + \varOmega\delta J - \upsilon\delta Q$ ) with the relation for the change in entropy δS=8πMδM. When the work is further extended with proper operation, the entropy of black hole is obtained almost the same as the Bekenstein-Hawking entropy of black hole. This is the entirely new method to obtain the change in entropy of Non-spinning black holes w.r.t. the radius of event horizon and Hawking entropy of black hole. We have also calculated their values for different types of test non-spinning black holes having masses 5–20M _⊙ found in X-ray binaries (Narayan, gr-qc/0506078v1, 2005).     

The fundamental cosmic distance scale: state of the art and the Gaia perspective

In recent papers we had developed a unified picture of black hole entropy and curvature which was shown to lead to Hawking radiation. It was shown that for any black hole mass, holography implies a phase space of just one quantum associated with the interior of the black hole. Here we study extremal rotating and charged black holes and obtain unique values for ratios of angular momentum to entropy, charge to entropy, etc. It turns out that these ratios can be expressed in terms of fundamental constants in nature, having analogies with other physical systems, like in condensed matter physics.     

Fading Hawking radiation

In this study, we explore a particular type Hawking radiation which ends with zero temperature and entropy. The appropriate black holes for this purpose are the linear dilaton black holes. In addition to the black hole choice, a recent formalism in which the Parikh-Wilczek’s tunneling formalism amalgamated with quantum corrections to all orders in ? is considered. The adjustment of the coefficients of the quantum corrections plays a crucial role on this particular Hawking radiation. The obtained tunneling rate indicates that the radiation is not pure thermal anymore, and hence correlations of outgoing quanta are capable of carrying away information encoded within them. Finally, we show in detail that when the linear dilaton black hole completely evaporates through such a particular radiation, entropy of the radiation becomes identical with the entropy of the black hole, which corresponds to “no information loss”.     

Effects of the Blandford–Znajek process on the evolution of the central black holes of accretion discs

The effects of the Blandford–Znajek (BZ) process on the evolution of the central black holes of accretion discs are investigated by an analytical method and numerical calculations in this paper. It is shown that the BZ process reduces the rates of change of some parameters of the black hole, such as mass, angular momentum, dimensionless angular momentum and temperature, and the evolution of the central black hole towards the extreme Kerr black hole is depressed effectively. However, the rate of change of entropy of the central black hole is augmented in the BZ process. In addition, the consistency of the BZ process with the three laws of black hole thermodynamics is discussed.     

Thermodynamical analysis of acoustic Schwarzschild black hole

In this paper, we analyze the thermodynamic properties of acoustic Schwarzschild black holes with its parameter. The study is conducted in the extended phase space displaying the phase transition. This phase transition is examined through Gibbs free energy, specific heat, and heat capacity. Later, we discuss the thermal stability of acoustic black holes through Hawking temperature by identifying their stable and unstable regions. We calculate the corrected entropy to examine the thermal fluctuations. Through the corrected entropy we observe that there is no fluctuation in the case of small black holes. We also discuss the energy emission process from acoustic black holes. Moreover, we employ the generalized uncertainty principle to obtain a modified Lagrangian equation. We analyze the tunneling and Hawking temperature of the acoustic Schwarzschild black hole after solving the field equations.     

Generalized uncertainty principle and quantum gravitational effects on tunneling rate of Reissner-Nordström black hole

It is shown that the Bekenstein-Hawking entropy of black holes can accept a correction that effects on the radiation tunneling probability. By assumption of a spatially flat universe accompanied with expansion of metric, we could obtain an expression for entropy of black hole that is changing with respect to time and Bekenstein-Hawking temperature.     

黑洞在顺行吸积和逆行吸积中的演化特征

分别在薄盘和厚盘两种情况下,讨论吸积盘的中心黑洞在顺行积和逆行吸积中的演化特征,结果表明,黑洞的温度和熵在逆行吸积与顺行吸积中的演化特征很不相同;在顺行吸积中黑洞的温度单调减小,而在逆行吸积中黑洞的温度存在一个极大值;在吸积的全过程中,黑洞的熵始终是增加的,而且逆行吸积中黑洞熵的变化率要比顺行吸积中的黑洞熵的变化率大得多,此外还讨论了在吸积过程中,黑洞质量的相对变化与黑洞自转的相关性。     

The distribution of supermassive black holes in the nuclei of nearby galaxies

The growth of supermassive black holes by merging and accretion in hierarchical models of galaxy formation is studied by means of Monte Carlo simulations. A tight linear relation between masses of black holes and masses of bulges arises if the mass accreted by supermassive black holes scales linearly with the mass-forming stars and if the redshift evolution of mass accretion tracks closely that of star formation. Differences in redshift evolution between black hole accretion and star formation introduce a considerable scatter in this relation. A non-linear relation between black hole accretion and star formation results in a non-linear relation between masses of remnant black holes and masses of bulges. The relation of black hole mass to bulge luminosity observed in nearby galaxies and its scatter are reproduced reasonably well by models in which black hole accretion and star formation are linearly related but do not track each other in redshift. This suggests that a common mechanism determines the efficiency for black hole accretion and the efficiency for star formation, especially for bright bulges.