That would be inferred from post #20, or I always meant it to be.
The shell is a sphere of the initial ejecta from the
Big Bang, that is, the component labeled as "symmetry-broken gravity".
It's only claim to being different from any of the other preceding Big Bang force components to come after it, is that it was "in the universe" before inflation.Inflation which propelled the growth of the universe, for a brief moment, beyond the speed of light. Making this initial "front" of expanding universe make-up very different from it's otherwise identical force components that followed inflation.
Sorry that I am missing seeing your impediment that hinders your ability find your answer on your own, without me holding your hand to the information location. Perhaps my wishes for transparency in wanting your free presence to ask such simple questions here, is cluttering the site to the point that some observers are getting lost. I can't fix that.
I will not ask anyone to not approach me with questions. I might be having the same issue of not seeing your questions, because of all the clutter, but, as you see, I did eventually. Thank you for bearing with me.