Einstein and Rastall Theories of Gravitation in Comparison

Understand

We profit by a recent paper of Visser claiming that Rastall gravity is equivalent to Einstein gravity to compare the two gravitational theories in a general way.

• Our conclusions are different from Visser's ones.
• We indeed argue that these two theories are not equivalent.
• In fact, Rastall theory of gravity is an "open" theory when compared to Einstein general theory of relativity.