I got a PM that raised a question about William Nelson's talk the significance of which I ventured to discuss a little bit in Cosmology forum:
So I will respond to the general thrust of the question here in case anyone else is interested.
The point is that based on some work by Ivan Agullo and Leonard Parker (Harvard Phd 1966?) some of the structure BEFORE inflation comes thru due to stimulated
So inflation does not wipe the slate clean. The inflationary period (if it occurred as is commonly supposed) is, in a sense, transparent.
We can see (signs of) the density map of what came before.
This is of considerable interest to Loop cosmology researchers because what came before, a bounce and a brief period of naturally faster-than-exponential expansion (called "superinflation"), is of considerable interest to them.
So in the Loop case we may be able to see back before inflation. And Ivan Agullo was invited to give a talk about this at the April meeting of the American Physical Society.