FUTURE OF THE UNIVERSE

We have discussed the early evolution of the Universe. We will now look at the evolution of the Universe into the distant future. In particular, will the Universe

• expand forever (open universe)
• collapse back on itself (closed universe)
• reach infinity and stop after an infinite amount of time (flat universe

and what will it look like when it reaches its final destination (or what will be the properties of its final state)?

Some Definitions

                    Three Solutions (Lambda = 0)

           Curvature, k     Omega    q(0)         Age

Open      negative, k < 0    < 1     < 1/2   2/(3H(now))-->1/H(now) 

Flat        flat, k = 0      = 1     = 1/2        2/(3H(now)) 

Closed    positive, k > 0    > 1     > 1/2       < 2/(3H(now)) 

How do we go about determining the ultimate fate of the Universe?

Tests for the Appropriate Solution

• Dynamical Tests: Mass
• Dynamical Tests: Peculiar Velocities
• Topological Tests (geometrical tests)
• Summary