New Bondi-type outgoing boundary condition for the Einstein equations with cosmological constant
New Bondi-type outgoing boundary condition for the Einstein equations with cosmological constant
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具有宇宙常数的爱因斯坦方程的新 Bondi 型传出边界条件
DOI：
10.1142/s0218271815500819
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发表时间：
2015
影响因子：
2.2
通讯作者：
Zhoujian Cao （曹周键）
中科院分区：
文献类型：
--
作者：
Xiaokai He （何孝凯）;Zhoujian Cao （曹周键）
上个世纪中期，Bondi等人提出了爱因斯坦方程的一个外向边界条件。近年来，越来越多的观测表明爱因斯坦方程应该包含一个非零的宇宙常数。具有正宇宙常数的时空渐近地接近于德西特空间。邦迪的原始边界条件对于这些渐进德西特时空是无效的。但对于渐近de Sitter时空，传统的共形平坦边界条件不考虑引力辐射。在这项工作中，一个新的Bondi型外向边界条件的基础上Bondi-Sachs坐标。在这个新的边界条件下，渐近de Sitter时空的引力波行为与渐近Minkowski时空的引力波行为相似。传统的共形平坦边界条件福尔斯属于新边界条件的一个特殊子类。
In the middle of last century, Bondi and his coworkers proposed an outgoing boundary condition for the Einstein equations. Recently, more and more observations imply that the Einstein equations should include a nonzero cosmological constant. A spacetime with a positive cosmological constant approaches to a de Sitter space asymptotically. Bondi's original boundary condition is not valid for these asymptotically de Sitter spacetimes. But the traditional conformally flat boundary condition excludes the gravitational radiation for the asymptotically de Sitter spacetimes. In this work, a new Bondi-type outgoing boundary condition based on Bondi–Sachs coordinates is considered. With this new boundary condition, the gravitational wave behavior for the asymptotically de Sitter spacetime is similar to the one for the asymptotically Minkowski spacetime. The traditional conformally flat boundary condition falls into a special subclass of the new boundary condition.