Trace
The trace of the Einstein tensor can be computed by contracting the equation in the definition with the metric tensor . In dimensions (of arbitrary signature):
The special case of 4 dimensions in physics (3 space, 1 time) gives, the trace of the Einstein tensor, as the negative of, the Ricci tensor's trace. Thus another name for the Einstein tensor is the trace-reversed Ricci tensor.
Read more about this topic: Einstein Tensor
Famous quotes containing the word trace:
“Of moral purpose I see no trace in Nature. That is an article of exclusively human manufacture—and very much to our credit.”
—Thomas Henry Huxley (1825–95)
“The land of shadows wilt thou trace
And look nor know each other’s face
The present mixed with reasons gone
And past and present all as one
Say maiden can thy life be led
To join the living with the dead
Then trace thy footsteps on with me
We’re wed to one eternity”
—John Clare (1793–1864)
“No trace of slavery ought to mix with the studies of the freeborn man.... No study, pursued under compulsion, remains rooted in the memory.”
—Plato (c. 427–347 B.C.)