Boltzmann brains and multiverse are logically distinct issues. A single universe with an eternal de Sitter future potentially has this problem. I regard any theory that predicts a Boltzmann brain majority as wrong, but it’s not clear how generic a prediction this is for eternal inflation, or even whether eternal inflation is the right cosmology (e.g. for the test case, Vasiliev gravity).
Interesting, I just came across the discussion here http://physics.stackexchange.com/questions/32979/why-arent-we-boltzmann-brains-in-an-infinite-universe where you gave the argument from immediate disintegration. This is what I’ve been thinking also (some theist friends of mine were attempting to “prove” that multiverse theories are crazy based on BB).
Boltzmann brains and multiverse are logically distinct issues. A single universe with an eternal de Sitter future potentially has this problem. I regard any theory that predicts a Boltzmann brain majority as wrong, but it’s not clear how generic a prediction this is for eternal inflation, or even whether eternal inflation is the right cosmology (e.g. for the test case, Vasiliev gravity).