2:Einstein Field Equations
Relates the geometry of spacetime, as given by a spacetime metric, to mass-energy contained within it.
- The gravitational field is the history of the geometry of a space-like hypersurface.
Matter/Energy curves spacetime and that in turn affects trajectories in it. For example:
- Precession of Mercury’s orbit.
- Deflection of light around the Sun.
Black Holes are vacuum solutions (i.e.: Tmn= 0 )
- Interaction of binary black holes occurs via their curvatures.