共查询到19条相似文献，搜索用时 203 毫秒
1.
用新Tortoise坐标变换计算Vaidya黑洞的熵 总被引：1，自引：0，他引：1
采用一种新的Tortoise坐标变换,约化视界附近Klein-Gordon方程,得到了黑洞的Hawking温度;并用薄膜模型计算了黑洞熵,得到了熵与视界面积成正比的Bekenstein关系.用这种Tortoise坐标变换,还可以使计算动态黑洞熵时所用的截断因子变得与静态和稳态情况相同. 相似文献
2.
牛振风 《河北北方学院学报(自然科学版)》2009,25(1)
目的 解决黑洞熵的发散问题.方法 利用广义不确定关系计算量子态数目,进而计算G-H-S黑洞的熵.结果 此方法不必引入截断因子,就避免了熵的发散问题,而且得到了黑洞熵与其视界面积成正比的结果.结论 利用广义不确定关系计算黑洞的熵,不必引入截断因子,就可避免熵的发散问题. 相似文献
3.
目的 计算研究de Sitter时空中黑洞熵和视界面积间的关系.方法 利用在砖墙模型基础上发展起来的膜模型分别计算了Schwarzschild黑洞、动态的Vaidya和带电Vaidya黑洞熵.结果 在de Sitter时空中这些稳态和动态黑洞的熵均和视界面积成正比. 结论 再一次说明了膜结构的合理性. 相似文献
4.
研究一般球对称带电蒸发黑洞视界附近粒子的能级交错，给出交错能级最大值的表达式，得出一般球对称带电蒸发黑洞非热辐射频率范围是随时间变化的结论． 相似文献
5.
牛振风 《河北北方学院学报(自然科学版)》2009,25(3):22-26
目的 计算变加速直线运动带电黑洞的熵.方法 在一种新的Tortoise坐标变换下,采用薄膜模型,讨论变加速直线运动带电黑洞的熵.结果 不但保证了熵与面积成正比的结论 ,而且得到了和静态一样简单的截断因子.结论 新Tortoise坐标变换比旧Tortoise坐标变换更具有优越性. 相似文献
6.
对于稳态的、几何薄光学厚的标准盘,在考虑到喷流存在时吸积物质角动量的损失的情况下,根据黑洞吸积盘系统的能量守恒与角动量守恒,把吸积盘和喷流作为一个整体,推导出了标准薄盘的辐射通量的解析表达式。研究结果表明,存在喷流时吸积盘的辐射通量会明显降低;同时吸积盘的辐射通量F随着黑洞的自转参数α＊的增大而明显增大,黑洞自转α＊=0．998时的通量值比α＊=0时的值高出3个数量级;该结论能很好地被天文观测所拟合。 相似文献
7.
在地球能源日益枯竭的今天,科学家在考虑能否利用黑洞内所蕴藏的巨大能量,即利用黑洞来发电。黑洞,是巨大恒星在其后期内爆、塌缩后形成的一种天体。由于黑洞的密度极大,于是在其周围形成了巨大的重力场,物质被吸入黑洞后,都无法逃遁,即使光也不例外,"黑洞"由此得名。虽然迄今为止天文学家还没有具体指出黑洞存在于何处,但黑洞的存在是毋庸置疑的。 相似文献
8.
首先对热力学第一定律的普适内涵作了较全面的阐述,其中尤其是对定律中的内能、功和热量各项的本质内涵,结合自引力存在情况下,对这些概念作了深刻的阐述.进一步对当今黑洞理论主流学派建立的黑洞热力学第一定律中的问题作了较详细的剖析,揭示了当今主流学派所建立的黑洞热力学弟一定律中的基本问题.在此基础上提出了复合热力学第一定律内涵的黑洞热力学第一定律.最后将我们建立的黑洞热力学第一定律应用于K-N黑洞中,较好地克服了当今主流学派在其黑洞热力学第一定律中所存在的矛盾. 相似文献
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10.
阐述了Adhoe网络恶意节点利用路由协议实施黑洞攻击的方法,通过仿真试验分析了黑洞攻击过程。并针对几个关键的性能指标分析了黑洞攻击对网络性能的影响,详细阐述了一种AODV协议改进方案。试验证明该方案可以有效减少黑洞攻击,从而提高网络性能。 相似文献
11.
利用广义不确定关系计算量子态数目，进而计算Vaidya-Bonner黑洞的熵,此方法与brick-wall模型相比，优点为不必引入截断因子，就避免了发散问题。 相似文献
12.
李固强 《西南大学学报(自然科学版)》2005,27(2):47-49
利用量子统计方法,直接计算Barriola-Vilenkin黑洞背景下玻色场和费米场的配分函数, 然后利用砖墙膜模型计算和讨论黑洞背景下玻色场和费米场的熵. 相似文献
13.
The presence of young massive stars orbiting on eccentric rings within a few tenths of a parsec of the supermassive black hole in the galactic center is challenging for theories of star formation. The high tidal shear from the black hole should tear apart the molecular clouds that form stars elsewhere in the Galaxy, and transport of stars to the galactic center also appears unlikely during their lifetimes. We conducted numerical simulations of the infall of a giant molecular cloud that interacts with the black hole. The transfer of energy during closest approach allows part of the cloud to become bound to the black hole, forming an eccentric disk that quickly fragments to form stars. Compressional heating due to the black hole raises the temperature of the gas up to several hundred to several thousand kelvin, ensuring that the fragmentation produces relatively high stellar masses. These stars retain the eccentricity of the disk and, for a sufficiently massive initial cloud, produce an extremely top-heavy distribution of stellar masses. This potentially repetitive process may explain the presence of multiple eccentric rings of young stars in the presence of a supermassive black hole. 相似文献
14.
The origin of jets emitted from black holes is not well understood; however, there are two possible energy sources: the accretion disk or the rotating black hole. Magnetohydrodynamic simulations show a well-defined jet that extracts energy from a black hole. If plasma near the black hole is threaded by large-scale magnetic flux, it will rotate with respect to asymptotic infinity, creating large magnetic stresses. These stresses are released as a relativistic jet at the expense of black hole rotational energy. The physics of the jet initiation in the simulations is described by the theory of black hole gravitohydromagnetics. 相似文献
15.
N Webb D Cseh E Lenc O Godet D Barret S Corbel S Farrell R Fender N Gehrels I Heywood 《Science (New York, N.Y.)》2012,337(6094):554-556
Relativistic jets are streams of plasma moving at appreciable fractions of the speed of light. They have been observed from stellar-mass black holes (~3 to 20 solar masses, M(⊙)) as well as supermassive black holes (~10(6) to 10(9) M(⊙)) found in the centers of most galaxies. Jets should also be produced by intermediate-mass black holes (~10(2) to 10(5) M(⊙)), although evidence for this third class of black hole has, until recently, been weak. We report the detection of transient radio emission at the location of the intermediate-mass black hole candidate ESO 243-49 HLX-1, which is consistent with a discrete jet ejection event. These observations also allow us to refine the mass estimate of the black hole to be between ~9 × 10(3) M(⊙) and ~9 × 10(4) M(⊙). 相似文献
16.
We show that the black hole in the x-ray binary Cygnus X-1 was formed in situ and did not receive an energetic trigger from a nearby supernova. The progenitor of the black hole had an initial mass greater than 40 solar masses, and during the collapse to form the approximately 10-solar mass black hole of Cygnus X-1, the upper limit for the mass that could have been suddenly ejected is approximately 1 solar mass, much less than the mass ejected in a supernova. The observations suggest that high-mass stellar black holes may form promptly, when massive stars disappear silently. 相似文献
17.
Black holes are most often detected by the radiation produced when they gravitationally pull in surrounding gas, in a process called accretion. The efficiency with which the hot gas radiates its thermal energy strongly influences the geometry and dynamics of the accretion flow. Both radiatively efficient thin disks and radiatively inefficient thick disks are observed. When the accreting gas gets close to the central black hole, the radiation it produces becomes sensitive to the spin of the hole and the presence of an event horizon. Analysis of the luminosities and spectra of accreting black holes has yielded tantalizing evidence for both rotating holes and event horizons. Numerical simulations imply that the relativistic jets often seen from accreting black holes may be powered in part by the spin of the hole. 相似文献
18.
The physical nature of ultraluminous x-ray sources is uncertain. Stellar-mass black holes with beamed radiation and intermediate black holes with isotropic radiation are two plausible explanations. We discovered radio emission from an ultraluminous x-ray source in the dwarf irregular galaxy NGC 5408. The x-ray, radio, and optical fluxes as well as the x-ray spectral shape are consistent with beamed relativistic jet emission from an accreting stellar black hole. If confirmed, this would suggest that the ultraluminous x-ray sources may be stellar-mass rather than intermediate-mass black holes. However, interpretation of the source as a jet-producing intermediate-mass black hole cannot be ruled out at this time. 相似文献
19.
Supermassive black hole binaries may exist in the centers of active galactic nuclei such as quasars and radio galaxies, and mergers between galaxies may result in the formation of supermassive binaries during the course of galactic evolution. Using the very-long-baseline interferometer, we imaged the radio galaxy 3C 66B at radio frequencies and found that the unresolved radio core of 3C 66B shows well-defined elliptical motions with a period of 1.05 +/- 0.03 years, which provides a direct detection of a supermassive black hole binary. 相似文献