In trying to calculate the theoretical mass of the matter neccessary for the universe to be a singularity the only previous potential was to include dark matter of roughly 1/2 of the known matter. Is it possible to work backwards in time and show that when the 2.7 degree background reaches its limit of zero what the radius of the known universe would be?

time would have to go forward for the temperature of the background radiation to drop. further back you go, the hotter the universe was.

Forget Schwarzschild, you need Friedmann–Lemaître–Robertson–Walker!

 

The Schwarzchild solution describes a spherically symmetric vacuum surrounding a non-rotating mass like a star or similar.

 

The Friedmann–Lemaître–Robertson–Walker solution describes homogeneous, isotropic expanding or contracting universe.

 

 

However, as insane_alien has stated, the temperature goes up as you go back in time.