Traditional Notation
Among those who use index notation for tensors, it is common to use the letter R to represent three different things:
- the Riemann curvature tensor: or
- the Ricci tensor:
- the scalar curvature: R
These three are then distinguished from each other by their number of indices: the Riemann tensor has four indices, the Ricci tensor has two indices, and the Ricci scalar has zero indices. Those not using an index notation usually reserve R for the full Riemann curvature tensor.
Read more about this topic: Scalar Curvature
Famous quotes containing the word traditional:
“We should have an army so organized and so officered as to be capable in time of emergency, in cooperation with the National Militia, and under the provision of a proper national volunteer law, rapidly to expand into a force sufficient to resist all probable invasion from abroad and to furnish a respectable expeditionary force if necessary in the maintenance of our traditional American policy which bears the name of President Monroe.”
—William Howard Taft (1857–1930)