[AndrewC]

First, I'm not sure what "force" you are referring to, and second,

Any that we know about.

I placed the light years in quotations, because, if I recall correctly, it could be that large although I also am familiar with the grapefruit size of the universe. The change would still apply.

Reference for the big size

Inflation

In order for inflation to solve the horizon problem, this causal region must be blown up to at least the size of the observable universe today

[longshadow]

****In order for inflation to solve the horizon problem, this causal region must be blown up to at least the size of the observable universe today****

I'm pretty sure they mean that the region AT THE TIME OF INFLATION must TODAY be at least the size of the observable Universe, which is exactly what 13 billion years of normal non-inflationary expansion does to to the Universe.

I still don't see what the point is that you are raising; can you cut to the chase -- time is running out for tonight's session.

[longshadow]

just found the answer to your question on your linked site, about three lines below the quote you used:

"Here the extra factor a(ti) / a(t0) accounts for the expansion between the end of inflation Ti ~ 10¹⁵ GeV and today, T0 ~ 10^-4 eV."

IOW, most of the "scale change" that they are talking about takes place AFTER the inflation stops, that is to say, it occurs through the normal non-inflationary expansion of the universe, as I opined in my previous reply.