Coordinate Conditions - Synchronous Coordinates

Synchronous Coordinates

Another particularly useful coordinate condition is the synchronous condition:

and

.

Synchronous coordinates are also known as Gaussian coordinates. They are frequently used in cosmology.

The synchronous coordinate condition is neither generally covariant nor Lorentz covariant. This coordinate condition resolves the ambiguity of the metric tensor by providing four algebraic equations that the metric tensor must satisfy.