Hello, I would like to ask if there is a standard explanation of decoherence in the universe as a whole. I can see how decoherence is responsible for the classical behavior of a measured macroscopic object in its environment. But what about the big picture? Is it thought that the entire universe began spontaneously decohering immediately after the Big Bang, and if so, what would be considered the 'measured object' and what was the environment? I'm obviously missing something, otherwise the first stars never could have formed. Links to good papers on this topic would be appreciated; I'm surprised that there are essentially only two Google results from searching the phrase "decoherence of the universe." Thank you.