'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
Mohammad Abdus Salam Salam adopted the forename "Mohammad" in 1974 in response to the anti-Ahmadiyya decrees in Pakistan, similarly he grew his beard. (; ; 29 January 192621 November 1996) was a Punjabi Pakistani theoretical physicist and a ...
, who showed that the particle level gravity approach can produce confinement and
asymptotic freedom
In quantum field theory, asymptotic freedom is a property of some gauge theories that causes interactions between particles to become asymptotically weaker as the energy scale increases and the corresponding length scale decreases.
Asymptotic fre ...
while not requiring a force behavior differing from an
inverse-square law, as does QCD. Sivaram published a review of this
bimetric theory
Bimetric gravity or bigravity refers to two different classes of theories. The first class of theories relies on modified mathematical theories of gravity (or gravitation) in which two metric tensors are used instead of one.
The second metric may ...
approach.
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
In physics, spacetime is a mathematical model that combines the three dimensions of space and one dimension of time into a single four-dimensional manifold. Spacetime diagrams can be used to visualize relativistic effects, such as why differ ...
geometry. In some cases, string theory recognizes important
duality between gravity-like and QCD-like theories, most notably the
AdS/QCD
In theoretical physics, the anti-de Sitter/quantum chromodynamics correspondence is a goal (not yet successfully accomplished) to describe quantum chromodynamics (QCD) in terms of a dual gravitational theory, following the principles of the AdS/C ...
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
References
Gravity
Particle physics
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