电磁驱动的异步问题

矩形线圈的平面垂直干均匀磁场,磁感应强度为B,线圈不动,磁场以速度vB向右运动.因通过线圈的磁通量变化,在线圈中产生感应电动势和感应电流i,磁场对电流i的安培力Fm方向向右,将驱使线圈也以速度v向右运动.显然,只有线圈的速度v小于磁场的速度vB──即异步才能有电磁感应,线圈也才能继续运动.以下我们来证明ν<νB. 设附图中的矩形线圈abed的质量为m,其回路电阻R,且在t=0时,ad边与磁场边界重合.t时刻后,磁场向右运动距离为vBt,线圈向古运动为x,则只有在面积l(vBt-x)上才有磁通量通过,即而感应电动势e及感应电流i分别为e及i的方向均由a至d…     

黑洞的Hawking辐射

运用Damour-Ruffini方法研究黑洞的Hawking辐射.在保持时空中总能量守恒的条件下,考虑辐射粒子对时空的反作用后,得到了黑洞视界处粒子出射率与Bekenstein-Hawking熵有关,辐射谱不再是严格的纯热谱.所得结果与他人的工作一致,且满足量子力学的幺正性原理. 关键词： Damour-Ruffini方法 Hawking辐射 能量守恒     

Quantum statistical entropy for Kerr－de Sitter black hole

Improving the membrane model by which the entropy of the black hole is studied, we study the entropy of the black hole in the non-thermal equilibrium state. To give the problem stated here widespread meaning, we discuss the (n 2)-dimensional de Sitter spacetime. Through discussion, we obtain that the black hole‘s entropy which contains two horizons (a black hole‘s horizon and a cosmological horizon) in the non-thermal equilibrium state comprises the entropy corresponding to the black hole‘s horizon and the entropy corresponding to the cosmological horizon. Furthermore, the entropy of the black hole is a natural property of the black hole. The entropy is irrelevant to the radiation field out of the horizon. This deepens the understanding of the relationship between black hole‘s entropy and horizon‘s area. A way to study the bosonic and fermionic entropy of the black hole in high non-thermal equilibrium spacetime is given.     

Canonical Entropy and Phase Transition of Rotating Black Hole

Recently, the Hawking radiation of a black hole has been studied using the tunnel effect method. The radiation spectrum of a black hole is derived. By discussing the correction to spectrum of the rotating black hole, we obtain the canonical entropy. The derived canonical entropy is equal to the sum of Bekenstein-Havcking entropy and correction term. The correction term near the critical point is different from the one near others. This difference plays an important role in studying the phase transition of the black hole. The black hole thermal capacity diverges at the critical point. However, the canonical entropy is not a complex number at this point. Thus we think that the phase transition created by this critical point is the second order phase transition. The discussed black hole is a five-dimensional Kerr-AdS black hole. We provide a basis for discussing thermodynamic properties of a higher-dimensional rotating black hole.     

任意加速运动的Kerr黑洞热辐射

给出了作任意加速运动同时又作转动的动态Kerr黑洞的辐射温度和视界面方程,视界面不再是球面.辐射温度与辐射谱分布不仅随时间变化,而且与空间方位角有关. 关键词：     

Sen黑洞熵与能斯特定理

避开求解黑洞背景下波动方程的困难,应用量子统计方法,直接求解轴对称Sen黑洞背景下Bose场和Fermi场的配分函数.然后利用改进的 brick-wall 方法-膜模型,计算黑洞背景下Bose场和Fermi场的熵.得到黑洞熵不但与黑洞的外视界面积有关，而且也是内视界面积的函数.在所得结论中不存在对数发散项与舍去项,也不存在黑洞视界外标量场或Dirac场为什么是黑洞熵疑难,并且给出粒子的自旋简并度对黑洞熵的影响. 当黑洞的辐射温度趋于绝对零度时,由黑洞内外视界面积决定的黑洞熵也趋于零,它满足能斯特定理,可视 关键词： 膜模型 黑洞熵 能斯特定理     

α模型中不固定多重数下的阶乘矩、粒子数关联矩

利用二维相空间自仿射分形的随机级联α模型,采用蒙特卡罗模拟的方法,研究了阶乘矩､粒子数关联矩在不固定多重数下,对应于多重数相对起伏强度n_f的依赖关系,得到:阶乘矩、粒子数关联矩依赖于多重数相对起伏n_f,但间歇指数一般不依赖于n_f,当n_f较小时这种依赖性得以消除.     

Radiation spectrum of rotating Gdel black hole and correction entropy

We study the Hawking radiation of the scalar field in the rotating Gdel black hole in minimal five-dimensional supergravity. We not only derive radiation spectra that satisfy the unitary principle but also obtain the correction term of Bekenstein-Hawking entropy. The conclusion will help us learn more about the rotating Gdel black hole in minimal five-dimensional supergravity. This provides a greater understanding of the thermal radiation of black holes.     

利用新的整体嵌入方法研究高维旋转黑洞的Hawking效应和Unruh效应

首先通过维数约化的方法,在事件视界附近将高维旋转时空线元化为二维度规(仅仅是(t－r)部分),然后利用新的整体嵌入方法研究了(1+1)维时空的Hawking温度(Unruh温度).研究结果验证了Banerjee和Majhi观点的正确性,同时将该观点推广到了高维旋转黑洞的研究,得到了高维旋转黑洞的Hawking 温度(Unruh温度). 关键词： 黑洞 高维旋转 Hawking效应 Unruh效应     

Entanglement Entropy of Reissner–Nordstrm Black Hole and Quantum Isolated Horizon

Based on the work of Ghosh and Pereze, who view the black hole entropy as the logarithm of the number of quantum states on the Quantum Isolated Horizon(QIH)§ the entropy of Reissner–Nordstr¨om black hole is studied.According to the Unruh temperature, the statistical entropy of quantum fields under the background of Reissner–Nordstr¨om spacetime is calculated by means of quantum statistics. In the calculations we take the integral from the position of QIH to infinity, so the obtained entropy is the entanglement entropy outside the QIH. In Reissner–Nordstr¨om spacetime it is shown that if only the position of QIH is properly chosen the leading term of logarithm of the number of quantum states on the QIH is equal to the leading term of the entanglement entropy outside the black hole horizon, and both are the Bekenstein–Hawking entropy. The results reveal the relation between the entanglement entropy of black hole and the logarithm of the number of quantum states.