'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 Pakistani theoretical physicist. He shared the 1 ...
, 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 theory, gauge theories that causes interactions between particles to become asymptotically weaker as the energy scale increases and the corresponding length scale decreases. (A ...
while not requiring a force behavior differing from an
inverse-square law
In science, an inverse-square law is any scientific law stating that the observed "intensity" of a specified physical quantity is inversely proportional to the square of the distance from the source of that physical quantity. The fundamental ca ...
, as does QCD. Sivaram published a review of this
bimetric theory approach.
Although this approach has not so far led to a recognizably successful
unification
Unification or unification theory may refer to:
Computer science
* Unification (computer science), the act of identifying two terms with a suitable substitution
* Unification (graph theory), the computation of the most general graph that subs ...
of strong and other forces, the modern approach of
string theory
In physics, string theory is a theoretical framework in which the point-like particles of particle physics are replaced by one-dimensional objects called strings. String theory describes how these strings propagate through space and intera ...
is characterized by a close association between
gauge forces and
spacetime
In physics, spacetime, also called the space-time continuum, is a mathematical model that fuses the three dimensions of space and the one dimension of time into a single four-dimensional continuum. Spacetime diagrams are useful in visualiz ...
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
References
Gravity
Particle physics
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