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:
“Superstition saw
Something it had never seen before:
Brown eyes that loved without a trace of fear,
Beauty so sudden for that time of year.”
—Jean Toomer (1894–1967)
“Yet ere I can say where—the chariot hath
Passed over them—nor other trace I find
But as of foam after the ocean’s wrath”
—Percy Bysshe Shelley (1792–1822)
““In your company a man could die,” I said, “a man could die and you wouldn’t even notice, there’s no trace of friendship, a man could die in your company.””
—Max Frisch (1911–1991)