【摘 要】
：
The quasi-local notion of an isolated horizon is employed to study the entropy of black holes without any particular symmetry in loop quantum gravity.The idea of characterizing the shape of a horizon by a sequence of local areas is successfully applied in
【机 构】
：
School of Physics and Technology,Xinjiang University,Urumqi 830046,China;Department of Physics,Beiji
【出 处】
：
中国科学：物理学 力学 天文学（英文版）
论文部分内容阅读
The quasi-local notion of an isolated horizon is employed to study the entropy of black holes without any particular symmetry in loop quantum gravity.The idea of characterizing the shape of a horizon by a sequence of local areas is successfully applied in the scheme to calculate the entropy by the S O(1,1) BF boundary theory matching loop quantum gravity in the bulk.The generating function for calculating the microscopical degrees of freedom of a given isolated horizon is obtained.Numerical computations of small black holes indicate a new entropy formula containing the quantum correction related to the partition of the horizon.Further evidence shows that,for a given horizon area,the entropy decreases as a black hole deviates from the spherically symmetric one,and the entropy formula is also well suitable for big black holes.
其他文献
文章首次探讨了公司层面软信息与硬信息之间的互动关系.以2003年～2016年间A股上市公司为样本,以高铁开通为自然实验,使用多期双重差分法,聚焦于公司最主要的硬信息财务报告的稳健性特征,研究发现,高铁开通后其所在地上市公司的财务报告稳健性明显下降,且公司信息环境越差时上述情形越明显.进一步的研究还发现,通过改变软信息提供者的行为从而增加软信息的数量和传播,并直接影响能够以“眼见为实”的方式判断信息真伪的有形项目的会计确认过程,是高铁开通降低财务报告稳健性的主要途径.在采用多种估计和推断方法、控制可能的遗漏
Achieving excellent strength-ductility synergy is a long-lasting research theme for structural materials.However,attempts to enhance strength usually induce a loss of ductility,i.e.,the strength-ductility trade-off.In the present study,the strength-ductil
It has been a half-decade since the first direct detection of gravitational waves,which signifies the coming of the era of the gravitational-wave astronomy and gravitational-wave cosmology.The increasing number of the detected gravitational-wave events ha
Quantum secure direct communication (QSDC) has been demonstrated in both fiber-based and free-space channels using atten-uated lasers.Decoy-state QSDC by exploiting four decoy states has been proposed to address the problem of photon-number-splitting atta
使用台指期权市场散户的日内逐笔交易和持仓高频数据,研究是否存在可以稳定获得正回报的老练散户.鉴于交易绩效可能受到幸运女神的垂青,应用“False Discovery Rate”的统计方法对散户的投资绩效做了多重假设检验,发现约2.21％的散户为老练投资者.他们偏好做多期权的策略,特别是看涨期权,以追求无限获利的可能性.接着分析其获利的来源.基于老练散户的委托档数据,构建了委托单深度失衡变量,发现它可以显著预测期权未来的价格,而且在更长期的预测中无价格反转,说明他们善于捕捉和分析全市场信息.进一步的研究表明
中国房地产市场通过贷款违约及其与银行业之间的耦合作用等渠道影响银行部门风险.基于持有共同资产网络模型,考虑上述两种渠道引发的银行业系统性风险.时间维度而言,房地产贷款违约造成的直接风险远小于降价抛售带来的间接风险.空间维度而言,5家大型商业银行、招商银行、浦发银行等是系统重要性银行,华夏银行、广发银行和招商银行等是系统脆弱性银行,个人住房抵押贷款等是系统重要性资产.研究发现资产结构、银行结构和加权资产结构等是重要的风险因素,系统性风险错配指数可以刻画中国银行业系统性风险状况.通过耦合作用分析发现,银行业系
Magnetic frustrations can enhance quantum fluctuations in spin systems and lead to exotic topological insulating states.When coupled to mobile electrons,they may give rise to unusual non-Fermi liquid or metallic spin liquid states whose nature has not bee
在有限理性框架下,建立了以市场基本面为参考点的平准基金行为异质性代理模型.该模型包括3类投资者:传统的价值派、技术派及新建立的稳定者.稳定者作为平准基金干预市场的角色代理,会根据市场真实波动与其干预阈值的相对大小动态调整干预深度,同时引导投资者信念的转换,以使价格的正、负反馈力量达到均衡,保持市场稳定.另外,对平准基金干预行为进行了计算实验及动力学性能分析,研究发现平准基金干预阈值、干预深度及市场特征参数是影响平抑效果的重要参数,其中干预深度对平抑效果的影响较大.
The emergence of the mobility edge(ME)has been recognized as an important characteristic of Anderson localization.The dif-ficulty in understanding the physics of the MEs in three-dimensional(3D)systems from a microscopic image encourages the development o
The ultrafast dynamics ofphotoexcited carriers and coherent phonons in ultrathin Bi2Te3 thermoelectric films are studied through transient differential transmission spectroscopy.An ultralow frequency coherent optical phonon at 0.16 THz emerges,especially