Numerical Relativity and the Discovery of Gravitational Waves

• Published in: Annalen der Physik Vol. 531; no. 8
• Main Author: Eisenstein, Robert A.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01-08-2019
• Subjects: Algorithms; black holes; coalescence; Computer simulation; Einstein; Einstein equations; general relativity; Gravitation; Gravitational waves; Numerical relativity; numerical solution of Einstein's equations; Relativity; Theory of relativity
• ISSN: 0003-3804; 1521-3889
• DOI: 10.1002/andp.201800348

Solving Einstein's equations precisely for strong‐field gravitational systems is essential to determining the full physics content of gravitational wave detections. Without these solutions it is not possible to infer precise values for initial and final‐state system parameters. Obtaining these solutions requires extensive numerical simulations, as Einstein's equations governing these systems are much too difficult to solve analytically. These difficulties arise principally from the curved, non‐linear nature of spacetime in general relativity. Developing the numerical capabilities needed to produce reliable, efficient calculations has required a Herculean 50‐year effort involving hundreds of researchers using sophisticated physical insight, algorithm development, computational technique, and computers that are a billion times more capable than they were in 1964 when computations were first attempted. The purpose of this review is to give an accessible overview for non‐experts of the major developments that have made such dramatic progress possible.
Solving Einstein's equations for strong‐field gravitational systems is essential to determining the physics content of gravitational wave detections. These solutions require extensive numerical simulations, as Einstein's equations are much too difficult to solve analytically. This has required 50 years of effort on the part of hundreds of researchers. This paper is an overview for non‐experts of the major developments that have made such progress possible.