Winicour Jeffrey
Albert Einstein Institute, Max Planck Institute for Gravitational Physics, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 USA.
Living Rev Relativ. 2012;15(1):2. doi: 10.12942/lrr-2012-2. Epub 2012 Jan 25.
I review the development of numerical evolution codes for general relativity based upon the characteristic initial-value problem. Progress in characteristic evolution is traced from the early stage of 1D feasibility studies to 2D-axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black-hole spacetime. Cauchy codes have now been successful at simulating all aspects of the binary black-hole problem inside an artificially constructed outer boundary. A prime application of characteristic evolution is to extend such simulations to null infinity where the waveform from the binary inspiral and merger can be unambiguously computed. This has now been accomplished by Cauchy-characteristic extraction, where data for the characteristic evolution is supplied by Cauchy data on an extraction worldtube inside the artificial outer boundary. The ultimate application of characteristic evolution is to eliminate the role of this outer boundary by constructing a global solution via Cauchy-characteristic matching. Progress in this direction is discussed.
我回顾了基于特征初值问题的广义相对论数值演化代码的发展历程。特征演化的进展从一维可行性研究的早期阶段，追溯到能够精确模拟相对论性恒星振荡和引力坍缩的二维轴对称代码，再到如今提供二元黑洞时空片段的三维代码。柯西代码现已成功地在人工构建的外边界内模拟了二元黑洞问题的各个方面。特征演化的一个主要应用是将此类模拟扩展到无限远零曲面，在那里可以明确计算出二元吸积和合并产生的波形。现在通过柯西 - 特征提取已经实现了这一点，其中特征演化的数据由人工外边界内提取世界管上的柯西数据提供。特征演化的最终应用是通过柯西 - 特征匹配构建全局解来消除这个外边界的作用。本文讨论了在这个方向上取得的进展。
