Strong gravity

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'Strong gravity' is a non-mainstream theoretical approach to particle confinement having both a cosmological scale and a particle scale gravity. In the 1960s, it was taken up as an alternative to the then young QCD theory by several theorists, including Abdus Salam, who showed that the particle level gravity approach can produce confinement and asymptotic freedom while not requiring a force behavior differing from an inverse-square law, as does QCD. [1] Sivaram published a review of this bimetric theory approach. [2]

Although this approach has not so far led to a recognizably successful unification of strong and other forces, the modern approach of string theory is characterized by a close association between gauge forces and spacetime geometry. In some cases, string theory recognizes important duality between gravity-like and QCD-like theories, most notably the AdS/QCD correspondence.

The concept of strong gravity follows from applying the potential gravitational energy to the term of heat in the equation of the first law of thermodynamics (), where the total energy is mass-energy and the work is also the kinetic energy: , becomes

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In strong interaction physics, light front holography or light front holographic QCD is an approximate version of the theory of quantum chromodynamics (QCD) which results from mapping the gauge theory of QCD to a higher-dimensional anti-de Sitter space (AdS) inspired by the AdS/CFT correspondence proposed for string theory. This procedure makes it possible to find analytic solutions in situations where strong coupling occurs, improving predictions of the masses of hadrons and their internal structure revealed by high-energy accelerator experiments. The most widely used approach to finding approximate solutions to the QCD equations, lattice QCD, has had many successful applications; however, it is a numerical approach formulated in Euclidean space rather than physical Minkowski space-time.

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Light-front quantization applications

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References

  1. Salam, Abdus; Sivaram, C. (1 January 1993). "Strong Gravity Approach to QCD and Confinement". Modern Physics Letters A. 8 (4): 321–326. Bibcode:1993MPLA....8..321S. doi:10.1142/S0217732393000325.
  2. Sivaram, C.; Sinha, K. (1977). "Strong gravity, black holes, and hadrons". Physical Review D. 16 (6): 1975–1978. Bibcode:1977PhRvD..16.1975S. doi:10.1103/PhysRevD.16.1975.