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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 Weinberg and Edward Witten shows that this is not possible in Lorentz covariant theories: massless particles with spin greater than one are forbidden. The AdS/CFT correspondence may be viewed as a loophole in their argument. However, in this case not only the graviton is emergent; a whole spacetime dimension is emergent, too.[1]

See also

Weinberg–Witten theorem

References

Okui, Takemichi (2006). "Probing composite gravity in colliders". Physical Review D. scitation.aip.org. 73 (7): 075012. arXiv:hep-ph/0511082. Bibcode:2006PhRvD..73g5012O. doi:10.1103/PhysRevD.73.075012. Retrieved 2008-07-08.

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Theories of gravitation
Standard
Newtonian gravity (NG)

Newton's law of universal gravitation Gauss's law for gravity Poisson's equation for gravity History of gravitational theory

General relativity (GR)

Introduction History Mathematics Exact solutions Resources Tests Post-Newtonian formalism Linearized gravity ADM formalism Gibbons–Hawking–York boundary term

Alternatives to
general relativity
Paradigms

Classical theories of gravitation Quantum gravity Theory of everything

Classical

Einstein–Cartan Bimetric theories Gauge theory gravity Teleparallelism Composite gravity f(R) gravity Infinite derivative gravity Massive gravity Modified Newtonian dynamics, MOND
AQUAL Tensor–vector–scalar Nonsymmetric gravitation Scalar–tensor theories
Brans–Dicke Scalar–tensor–vector Conformal gravity Scalar theories
Nordström Whitehead Geometrodynamics Induced gravity Chameleon Pressuron Degenerate Higher-Order Scalar-Tensor theories

Quantum-mechanical

Unified-field-theoric

Kaluza–Klein theory
Dilaton Supergravity

Unified-field-theoric and
quantum-mechanical

Noncommutative geometry Semiclassical gravity Superfluid vacuum theory
Logarithmic BEC vacuum String theory
M-theory F-theory Heterotic string theory Type I string theory Type 0 string theory Bosonic string theory Type II string theory Little string theory Twistor theory
Twistor string theory

Generalisations /
extensions of GR

Liouville gravity Lovelock theory (2+1)-dimensional topological gravity Gauss–Bonnet gravity Jackiw–Teitelboim gravity

Pre-Newtonian
theories and
toy models

Aristotelian physics CGHS model RST model Mechanical explanations
Fatio–Le Sage Entropic gravity Gravitational interaction of antimatter Physics in the medieval Islamic world Theory of impetus

Related topics

Graviton

Physics Encyclopedia

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