QUASILOCAL ENERGY FOR STATIONARY AXISYMMETRIC EMDA BLACK HOLE

By using Brown-York quasilocal energy theory we calculate the quasilocal energy of a stationary axisymmetic EMDA black hole and explore the universality of Martinez's conjecture in string theory. We show that the energy is positive and monotonically decreases to the ADM mass at spatial infinity, and the Martinez's conjecture, the Brown-York quasilocal energy at the outer horizon reduces to twice its irreducible mass, is still valid for stationary axisymmetric EMDA black hole. From the result we also find that the Kerr-Sen spacetime keeps up with Martinez's conjecture. This is different from the Bose-Naing result that the quasilocal energy of the Kerr-Sen spacetime does not approach the Martinez's conjecture.     

银河系中心超大质量黑洞的探索历程

经过逾半个世纪的探索,天文学家确认在我们银河系的中心存在一个4百万倍太阳质量的致密天体,很可能是爱因斯坦广义相对论所预言的黑洞。文章简要回顾了探索这个大质量致密天体过程中的若干里程碑。     

Tunneling Radiation from a Static Spherically Symmetric Black Hole Surrounded by Quintessence

By extending the Parikh-Wilczek tunneling framework, we investigate the tunneling radiation of uncharged massless particles from a static spherically symmetric black hole surrounded by quintessence. The results are consistent with an underlying unitary theory.     

包围有暗能量黑洞的Hawking辐射修正

运用由Banerjee和Majhi所发展的非半经典近似的Hamiliton-Jacobi方法,计算了被暗能量包围的黑洞温度和熵,得到了修正后的温度和熵.在修正后的熵中,面积定理包含面积对数修正和面积幂的倒数。     

Quantum Non-thermal Effect from Black Holes Surrounded by Quintessence

We present a short and direct derivation of Hawking radiation as a tunneling process across the horizon and compute the tunneling probability. Considering the self-gravitation and energy conservation, we use the Keski Vakkuri, Kraus, and Wilczek （KKW） analysis to compute the temperature and entropy of the black holes surrounded by quintessence and obtain the temperature and entropy are different from the Hawking temperature and the Bekenstein- Hawking entropy. The result we get can offer a possible mechanism to deal with the information loss paradox because the spectrum is not purely thermal.     

含整体单极子黑洞场中的吸附和辐射

本文研究了在含整体单极子的黑洞场中质量亏损效应,计算了被吸附的(落向质量中心的)中性粒子的质量亏损,进而计算了被吸附的质量球壳以及极限情况下质量球的质量亏损.这些物质的质量亏损最终将转化为能量辐射.关键词：广义相对论整体单极子黑洞质量亏损     

Tunneling Radiation from a Static Spherically Symmetric Black Hole Surroundedby Quintessence

By extending the Parikh-Wilczek tunneling framework, we investigate the tunneling radiation of uncharged massless particles from a static spherically symmetric black hole surrounded by quintessence. The results are consistent with an underlying unitary theory.     

黑洞与奇点

黑洞可以说是引力最极端的体现,其视界内是个连光也逃不出去的时空区域。近来黑洞在天文观测方面取得令人惊讶的发展,这其中包括：黑洞碰撞的引力波探测以及M87 星系的超大质量黑洞的所谓第一张黑洞照片。但是在理论的层面上,黑洞物理尚有许多未解之谜。其中,信息遗失的悖论是最有名的。但是,有另一个问题至少和信息的丢失一样{甚至更加{令人费解的,就是黑洞内部的奇点性质。时空奇点是广义相对论本身无法描述的,在那里究竟发生什么事？黑洞内部的奇点和宇宙大爆炸时的奇点有何不同？奇点是否会裸露在黑洞外面？所谓“宇宙监督猜想”的假设目前有何进展？我们在这篇半科普的文章中简单的介绍这些课题,希望本文章对物理和数学的本科生有所帮助。     

Quantum Non-thermal Effect from Black Holes Surrounded by Quintessence

We present a short and direct derivation of Hawking radiation as atunneling process across the horizon and compute the tunneling probability. Considering the self-gravitation and energy conservation, we use the Keski-Vakkuri, Kraus, and Wilczek (KKW) analysis to compute the temperature and entropy of the black holes surrounded by quintessence and obtain the temperature and entropy are different from the Hawking temperature and theBekenstein-Hawking entropy. The result we get can offer a possiblemechanism to deal with the information loss paradox because thespectrum is not purely thermal.     

Metric Expansion from Microscopic Dynamics in an Inhomogeneous Universe

Theories with ingredients like the Higgs mechanism, gravitons, and inflaton fields rejuvenate the idea that relativistic kinematics is dynamically emergent. Eternal inflation treats the Hubble constant H as depending on location. Microscopic dynamics implies that H is over much smaller lengths than pocket universes to be understood as a local space reproduction rate. We illustrate this via discussing that even exponential inflation in TeV-gravity is slow on the relevant time scale. In our on small scales inhomogeneous cosmos, a reproduction rate H depends on position. We therefore discuss Einstein-Strauss vacuoles and a Lindquist-Wheeler like lattice to connect the local rate properly with the scaling of an expanding cosmos. Consistency allows H to locally depend on Weyl curvature similar to vacuum polarization. We derive a proportionality constant known from Kepler＇s third law and discuss the implications for the finiteness of the cosmological constant.     

认识黑洞的首个直接“视觉”证据

2019年4月10日,由黑洞事件视界望远镜（Event Horizon Telescope,EHT）合作组织协调召开新闻发布会,全球多地同时发布了黑洞的首个直接“视觉”证据。作为人类捕获的首张黑洞照片,它展示了5500万光年外的椭圆星系M87中心超大质量黑洞的图像,看到了黑洞“阴影”和周围环绕的新月状光环。EHT的此次观测结果从强引力场的角度验证了爱因斯坦广义相对论,有助于研究黑洞的吸积以及喷流的产生。文章着重介绍为什么给黑洞“拍照”,选择哪些黑洞模特“拍照”,如何给黑洞“拍照”,获得的数据经过怎样的后期处理和分析才能生成大家看到的“照片”;此外还将介绍在此次合作项目里的中国贡献,最后对黑洞高分辨率成像领域进行展望。     

Metric Expansion from Microscopic Dynamics in an Inhomogeneous Universe

Theories with ingredients like the Higgs mechanism, gravitons, and inflatonfields rejuvenate the idea that relativistic kinematics is dynamicallyemergent. Eternal inflation treats the Hubble constant H as depending onlocation. Microscopic dynamics implies that H is over much smaller lengthsthan pocket universes to be understood as a local space reproduction rate.We illustrate this via discussing that even exponential inflation inTeV-gravity is slow on the relevant time scale. In our on small scalesinhomogeneous cosmos, a reproduction rate H depends on position. We therefore discuss Einstein-Strauss vacuoles and a Lindquist-Wheeler like lattice to connect the local rate properly with the scaling of an expanding cosmos. Consistency allows H to locally depend on Weyl curvature similar to vacuum polarization. We derive a proportionality constant known from Kepler's third law and discuss the implications for the finiteness of the cosmological constant.