Scalar theories of gravitation

Scalar theories of gravitation are field theories of gravitation in which the gravitational field is described using a scalar field, which is required to satisfy some field equation.

Note: This article focuses on relativistic classical field theories of gravitation. The best known relativistic classical field theory of gravitation, general relativity, is a tensor theory, in which the gravitational interaction is described using a tensor field.

The prototypical scalar theory of gravitation is Newtonian gravitation. In this theory, the gravitational interaction is completely described by the potential ${\displaystyle \Phi }$, which is required to satisfy the Poisson equation (with the mass density acting as the source of the field). To wit:

${\displaystyle \Delta \Phi =4\pi G\rho }$, where

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