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Complex spacetime is a mathematical framework that combines the concepts of complex numbers and spacetime in physics. In this framework, the usual real-valued coordinates of spacetime are replaced with complex-valued coordinates. This allows for the inclusion of imaginary components in the description of spacetime, which can have interesting implications in certain areas of physics, such as quantum field theory and string theory.
In gravitational theory, the Bondi–Metzner–Sachs (BMS) group, or the Bondi–van der Burg–Metzner–Sachs group, is an asymptotic symmetry group of asymptotically flat, Lorentzian spacetimes at null infinity. It was originally formulated in 1962 by Hermann Bondi, M. G. van der Burg, A. W. Metzner and Rainer K. Sachs in order to investigate the flow of energy at infinity due to propagating gravitational waves. Half a century later, this work of Bondi, van der Burg, Metzner, and Sachs is considered pioneering and seminal. In his autobiography, Bondi considered the 1962 work as his "best scientific work".
References
- ↑ Einstein, Albert; Straus, E. G. (October 1945). "A Generalization of the Relativistic Theory of Gravitation" (PDF). Annals of Mathematics. 46 (4): 578–584. doi:10.2307/1969197. JSTOR 1969197.
- ↑ Sachs, Mendel (1970-04-11). "On the Most General Form of a Field Theory from Symmetry Principles". Nature. 226 (5241): 138–139. Bibcode:1970Natur.226..138S. doi:10.1038/226138a0. PMID 16057133. S2CID 4177286.
- ↑ Sachs, Mendel (2010), Physics of the Universe, Imperial College Press, London, ISBN 978-1-84816-532-8