For , -dimensional Minkowski space is the Lorentzian manifold whose underlying smooth manifold is the Cartesian space and whose pseudo-Riemannian metric is at each point the Minkowski metric.
This is naturally a spacetime.
Minkowski spacetimes is a stable? solution of the vacuum Einstein equations.
This is due to (ChristodoulouKlainerman 1993).
Gravitational stability of Minkowski space is proven in