Gia Dvali
Gia Dvali
We describe an attempt of string theoretic derivation of the Gibbons-Hawking entropy. Despite not admitting a de Sitter vacuum, the string theory, by the power of open-close correspondence, captures the Gibbons-Hawking entropy as the entrop...
Ruth Gregory,Samaya Nissanke
Ruth Gregory
We briefly overview the case for using black holes as a discriminator for theories of gravity. The opportunities and challenges for the various observational experiments are outlined, and key questions for the community identified. This not...
Nonminimal coupling, quantum scalar field stress-energy tensor and energy conditions on global anti-de Sitter space-time [0.03%]
非极小耦合、量子标量场应力-能量张量和全局反德西特空间的能条件
Sivakumar Namasivayam,Elizabeth Winstanley
Sivakumar Namasivayam
We compute the renormalized expectation value of the stress-energy tensor operator for a quantum scalar field propagating on three-dimensional global anti-de Sitter space-time. The scalar field has general mass and nonminimal coupling to th...
Height-function-based 4D reference metrics for hyperboloidal evolution [0.03%]
基于高度函数的双曲化演化的4D参考度量标准
Alex Vañó-Viñuales,Tiago Valente
Alex Vañó-Viñuales
Hyperboloidal slices are spacelike slices that reach future null infinity. Their asymptotic behaviour is different from Cauchy slices, which are traditionally used in numerical relativity simulations. This work uses free evolution of the fo...
Neutron star merger remnants [0.03%]
中子星并合残余体
Sebastiano Bernuzzi
Sebastiano Bernuzzi
Binary neutron star mergers observations are a unique way to constrain fundamental physics and astrophysics at the extreme. The interpretation of gravitational-wave events and their electromagnetic counterparts crucially relies on general-r...
The Dirac equation across the horizons of the 5D Myers-Perry geometry: separation of variables, radial asymptotic behaviour and Hamiltonian formalism [0.03%]
五维Myers-Perry几何视界中的Dirac方程：变量分离，径向渐近行为和Hamilton形式主义
Qiu Shi Wang
Qiu Shi Wang
We analytically extend the 5D Myers-Perry metric through the event and Cauchy horizons by defining Eddington-Finkelstein-type coordinates. Then, we use the orthonormal frame formalism to formulate and perform separation of variables on the ...
Geodesics and gravitational waves in chaotic extreme-mass-ratio inspirals: the curious case of Zipoy-Voorhees black-hole mimickers [0.03%]
极端质量比并合中的测地线和引力波：Zipoy-Voorhees黑洞模拟器的特殊情况
Kyriakos Destounis,Giulia Huez,Kostas D Kokkotas
Kyriakos Destounis
Due to the growing capacity of gravitational-wave astronomy and black-hole imaging, we will soon be able to emphatically decide if astrophysical dark objects lurking in galactic centers are black holes. Sgr A*, one of the most prolific astr...
Andrea Giusti,Serena Giardino,Valerio Faraoni
Andrea Giusti
We refine and slightly enlarge the recently proposed first-order thermodynamics of scalar-tensor gravity to include gravitational scalar fields with timelike and past-directed gradients. The implications and subtleties arising in this situa...
Detection of early-universe gravitational-wave signatures and fundamental physics [0.03%]
早期宇宙的引力波信号检测和基础物理研究
Robert Caldwell,Yanou Cui,Huai-Ke Guo et al.
Robert Caldwell et al.
Detection of a gravitational-wave signal of non-astrophysical origin would be a landmark discovery, potentially providing a significant clue to some of our most basic, big-picture scientific questions about the Universe. In this white paper...
Penrose junction conditions with [Formula: see text] : geometric insights into low-regularity metrics for impulsive gravitational waves [0.03%]
具有[公式见PDF]的彭若斯联合条件：低正则性度量的几何见解以描述脉冲引力波
Jiří Podolský,Roland Steinbauer
Jiří Podolský
Impulsive gravitational waves in Minkowski space were introduced by Roger Penrose at the end of the 1960s, and have been widely studied over the decades. Here we focus on nonexpanding waves which later have been generalized to impulses trav...