Horizon data: existence results and a near-horizon equation on general null hypersurfaces [0.03%]
水平集数据：存在结果及一般光线双曲面的近水平集方程
Miguel Manzano,Marc Mars
Miguel Manzano
In a spacetime ( M , g ) , a horizon is a null hypersurface where the deformation tensor K : = £ η g of a null and tangent vector η satisfies certain restrictions. In this work, we develop a formalism to study the geometry ...
Moriz L Frauenberger,James D E Grant,Roland Steinbauer
Moriz L Frauenberger
In 1962, Ehlers and Kundt conjectured that plane waves are the only class of complete Ricci-flat pp-waves, i.e. metrics on R 4 of the form d s 2 = 2 d u d v + d x 2 + d y 2 + H ( x , y , u ) d u 2 . Recently, Flores and Sánchez gave a...
Gregory J Galloway,Eric Ling
Gregory J Galloway
In a previous paper [9], we proved the following singularity theorem applicable to cosmological models with a positive cosmological constant: if a four-dimensional spacetime satisfying the null energy condition contains a compact Cauchy sur...
The [Formula: see text] -inextendibility of some spatially flat FLRW spacetimes [0.03%]
某些各向同性宇宙模型的不可延拓性
Eric Ling
Eric Ling
Utilizing some of Sbierski's recent C 0 -inextendibility techniques [18], we prove the C 0 -inextendibility of a class of spatially flat FLRW spacetimes without particle horizons. ...
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 ...