**Problem Set #5**

**ASTR 3830**

- Show
that if k=0 and P=0, a steady state universe requires that L=0, r=0 and
*a*is undefined.

- Einstein
speculated that k=1 and that
*a*was constant to create a finite, steady universe. Show that this implies:

Then derive a formula for the density of universe.

Please note, you may have trouble deriving this from the Einstein equations presented in class. Our treatment of L was incomplete. I suggest you go to the library and find the full forms in a textbook.

- In
your own words describe why we think that matter-antimatter asymmetry was 10
^{-9}in the early universe.