Comparing results for a global metric from analytical perturbation theory and a numerical code
Javier E. Cuchí, Alfred Molina, Eduardo Ruiz
备注：
4 pages, 2 figures, 1 table. Contribution to the conference proceedings of "Progress in Mathematical Relativity, Gravitation and Cosmology", ERE2012, University of Minho, Portugal
We compare the results obtained from analytical perturbation theory and the AKM numerical code for an axistationary spacetime built from matching a rotating perfect fluid interior with the equation of state $ε-3p=4B$ of the simple MIT bag model and an asymptotically flat exterior. We discuss the behaviour of the error in the metric components of the analytical approximation going to higher orders. Additionally, we check and comment the errors in multipole moments, central pressure and some other physical properties of the spacetime.
Comparing a gauge-invariant formulation and a "conventional complete gauge-fixing approach" for $l=0,1$ mode perturbations on the Schwarzschild background spacetime
Covariant cosmography in the presence of local structures: comparing exact solutions and perturbation theory
National Institute for Theoretical & Computational Sciences（国家理论与计算科学研究所）；Aix Marseille Univ, Université de Toulon, CNRS, CPT（艾克斯-马赛大学，土伦大学，法国国家科学研究中心，理论物理中心）；Department of Physics & Astronomy, Queen Mary University of London（伦敦玛丽女王大学物理与天文系）；Department of Physics & Astronomy, University of the Western Cape（西开普大学物理与天文系）
Gauge dependence of scalar-induced gravitational waves from isocurvature perturbations: Analytical results
Institute for Advanced Study & School of Physical Science and Technology, Soochow University（苏州大学前沿研究院与物理科学与技术学院）；School of Physics, University of Electronic Science and Technology of China（电子科技大学物理学院）
Perturbations of Extremal Kerr Spacetime: Analytic Framework and Late-time Tails
基于Mano，Suzuki and Takasugi（MST）提出的Teukolsky方程，我们发展了一个完整而系统的分析方法来研究极端Kerr时空的场扰动.给出了径向解和频域格林函数的特殊函数无穷级数解析表达式。作为一个应用程序，我们计算，第一次，领先的晚时间的行为，由于分支点在零频率的标量，引力和电磁场扰动和关闭的事件视界。我们还使用MST方法计算了分支点附近的格林函数模式在超辐射束缚频率的领先行为，并表明这种行为与文献中使用不同方法的现有结果一致。
Linear perturbations of an exact gravitational wave in the Bianchi IV universe
Tomsk State Pedagogical University（托木斯克国立师范大学）；Tomsk State University of Control Systems and Radioelectronics（托木斯克国立控制与无线电电子大学）；National Research Tomsk State University（托木斯克国立研究大学）
