There will be no collapse.. but there will be a fading away.
as matter reaches the outer edges of space, the rate of spatial motion raises the flow rate of time, and all matter will eventually decay and break down to the orginal spatial tension, which then gives its energy up, to return to the lower energy 3D space had when the universe was new...
thus space bleeds out all its energy back to the source outside our space, until space itself begins to emit energy and return to the zero energy state from which it all began.
see my thread.. Mosheh thezions cosmology.

its like a collapse.. but its not exactly.
-MT