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
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Kaluza–Klein theory
Dilaton Supergravity
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Noncommutative geometry Semiclassical gravity Superfluid vacuum theory
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Twistor string theory
Generalisations /
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Pre-Newtonian
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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
Hellenica World - Scientific Library
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