Questions tagged [gravity-theory]

Gravity is the weakest of the four fundamental forces of physics. The standard gravity theory is Newton's law of universal gravitation and general theory of relativity (proposed by Albert Einstein in 1915, and David Hilbert, and others). Alternative formulations include string theory, entanglement and others.

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Is there a high level reason why the inverse square law of gravitation yields periodic orbits without precession?

Given a spherically symmetric potential $V: {\bf R}^d \to {\bf R}$, smooth away from the origin, one can consider the Newtonian equations of motion $$ \frac{d^2}{dt^2} x = - (\nabla V)(x)$$ for a ...
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Yang-Mills theory v.s. Kaluza–Klein theory: Classical actions

In general Yang-Mills theory [1] seems to be different from the dimensional reduced Kaluza–Klein theory. However, the historical account was that people tried to trace back the origin of non-Abelian ...