Higher-dimensional Einstein gravity
- Higher-dimensional Einstein gravity
Higher-dimensional Einstein gravity is any of various physical theories that attempt to generalise to higher dimensions various results of the well established theory of standard (four-dimensional) Einstein gravity, that is, general relativity. This attempt at generalisation has been strongly influenced in recent decades by string theory.
At present, this work can probably be most fairly described as extended theoretical speculation. Currently, it has no "direct" observational and experimental support, in contrast to four-dimensional general relativity. However, this theoretical work has led to the possibility of proving the existence of extra dimensions. This is best demonstrated by the proof of Harvey Reall and Roberto Emparan that there is a 'black ring' solution in 5 dimensions. If such a 'black ring' could be produced in a particle accelerator such as the Large Hadron Collider, this would provide the evidence that higher dimensions exist.
Exact solutions
The higher-dimensional generalization of the Kerr metric was discovered by Myers and Perry. Like the Kerr metric, the Myers-Perry metric has spherical horizon topology. The construction involves making a Kerr-Schild ansatz; by a similar method, the solution has been generalized to include a cosmological constant.The black ring is a solution of five-dimensional general relativity. It inherits its name from the fact that its event horizon is topologically S1 × S2. This is in contrast to other known black hole solutions in five dimensions which have horizon topology S3.See also black string.
Black hole uniqueness
In four dimensions, Hawking proved that the topology of the event horizon of a black hole must be spherical. Because the proof uses the Gauss-Bonnet theorem, it does not generalize to higher dimensions. The discovery of black ring solutions in five dimensions shows that other topologies are allowed in higher dimensions, but it is unclear precisely which topologies are allowed. It has been shown that the horizon must be of positive Yamabe type, meaning that it must admit a metric of positive scalar curvature.
ee also
* General relativity
* Kaluza-Klein theory
Wikimedia Foundation.
2010.
Look at other dictionaries:
List of things named after Albert Einstein — This is a list of things named after Albert Einstein. Scientific and mathematical concepts * Higher dimensional Einstein gravity * Einstein solid * Einstein force * Einstein s constant * Einstein relation (kinetic theory) * Stark Einstein law *… … Wikipedia
Einstein manifold — In differential geometry and mathematical physics, an Einstein manifold is a Riemannian or pseudo Riemannian manifold whose Ricci tensor is proportional to the metric. They are named after Albert Einstein because this condition is equivalent to… … Wikipedia
Loop quantum gravity — Not to be confused with the path integral formulation of LQG, see spin foam. This article is about LQG in its Canonical formulation.. Beyond the Standard Model … Wikipedia
Conformal gravity — is a generic name for gravity theories which are invariant under conformal transformations in the Riemannian geometry sense; more accurately, they are invariant under Weyl transformations where gab is the metric tensor and Ω(x) is a function on… … Wikipedia
Massive gravity — In theoretical physics, massive gravity is a particular generalization of general relativity studied by Hendrik van Dam, Martinus J. G. Veltman (1) , and Vladimir E. Zakharov.(2) One assumes that physics takes place in Minkowski space and gravity … Wikipedia
Composite gravity — In theoretical physics, composite gravity refers to models that attempted to derive general relativity in a framework where the graviton is constructed as a composite bound state of more elementary particles, usually fermions.A theorem by Steven… … Wikipedia
Quantum gravity — is the field of theoretical physics attempting to unify quantum mechanics, which describes three of the fundamental forces of nature (electromagnetism, weak interaction, and strong interaction), with general relativity, the theory of the fourth… … Wikipedia
Bose–Einstein condensate — A Bose–Einstein condensate (BEC) is a state of matter of bosons confined in an external potential and cooled to temperatures very near to absolute zero (val|0|u=K, val| 273.15|u=°C, or val| 459.67|u=°F ). Under such supercooled conditions, a… … Wikipedia
Anti-gravity — Antigrav redirects here. For the EyeToy video game, see EyeToy: AntiGrav. Anti gravity is the idea of creating a place or object that is free from the force of gravity. It does not refer to the lack of weight under gravity experienced in free… … Wikipedia
Introduction to general relativity — General relativity (GR) is a theory of gravitation that was developed by Albert Einstein between 1907 and 1915. According to general relativity, the observed gravitational attraction between masses results from the warping of space and time by… … Wikipedia
