anti-de Sitter space

noun

an·​ti-de Sit·​ter space ¦an-ˌtī-də-¦si-tər- 

¦an-tē-

physics

: the simplest hypothetical space-time that has negative curvature

The simplest spacetime with positive curvature is called de Sitter space, after Willem de Sitter, the Dutch physicist who introduced it. Many cosmologists believe that the very early universe was close to being a de Sitter space. The far future may also be de Sitter-like because of cosmic acceleration. Conversely, the simplest negatively curved spacetime is called anti-de Sitter space. It is similar to hyperbolic space except that it also contains a time direction. Unlike our universe, which is expanding, anti-de Sitter space is neither expanding nor contracting. It looks the same at all times.

—Juan Maldacena, Scientific American, November 2005

compare de sitter space

Word History

Etymology

anti- entry 1 + de Sitter space

First Known Use

1998, in the meaning defined above

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