Intuitively, a Cauchy surface is a plane in space-time which is like an instant of time; its significance is that giving the initial conditions on this plane determines the future (and the past) uniquely.
More precisely, a Cauchy surface is any subset of space-time which is intersected by every non-spacelike, inextensible curve, i.e. any causal curve, exactly once.
A partial Cauchy surface is a hypersurface which is intersected by any causal curve at most once.
The name is for Augustin Louis Cauchy.
Read more about Cauchy Surface: Discussion, Cauchy Horizon
Famous quotes containing the word surface:
“We say justly that the weak person is flat, for, like all flat substances, he does not stand in the direction of his strength, that is, on his edge, but affords a convenient surface to put upon. He slides all the way through life.... But the brave man is a perfect sphere, which cannot fall on its flat side and is equally strong every way.”
—Henry David Thoreau (1817–1862)