# What is the Unit of the Metric Tensor?

1. May 27, 2004

### Antonio Lao

If the cosmological constant, $\Lambda$ has units of reciprocal time squared then what is the unit for the metric tensor, $g_{ij}$?

2. May 27, 2004

### franznietzsche

It has no units. A metric tensor in any coordinate can have no units, just look at how the components of a diagonal metric tensor fits into the distance formula, if it had units the units on the left would not match the units on teh right.

3. May 28, 2004

### Antonio Lao

franznietzsche,

Thanks. But I'm still not clear why the righthand side of Einstein's field equations, the momentum-energy tensor has components of different units (units in pressures, and units in densities).

4. May 29, 2004

### Russell E. Rierson

Here is an excellent GR tutorial:

http://math.ucr.edu/home/baez/gr/outline2.html

5. May 29, 2004

### Antonio Lao

Russell,

Thanks. Will start studying this GR tutorial.