The Cosmological Constant

Here's the definition from my favourite resource:
cosmological constant: "A force of repulsion (a kind of antigravity) that arises naturally in some theories of the very early Universe involving the break-up of a primordial superforce into the three* forces of nature known today. The effect of the cosmological constant is to cause an extremely rapid expansion of the universe in the first split-second of its existance, before the constant fades away to zero, leaving the more sedate expansion that we see today."
You'll note in this definition that it says the constant fades away to zero. If I understand the theory mentioned before correctly, they are saying that maybe this constant did not fade away to zero, but is still present.

*three, or two, or one force, depending on which theory you like. If you're in 211 and you don't know what I mean here, you should have read Chapter 6 more thoroughly. Go back and look for the Grand Unification Theories (GUT's), there's a little excerpt about them.