In the heat death of the universe? where would it get its energy needed to fluctuate?
Just ask yourself this question ? Are QFT-like processes taking place in this particular case (strong, weak interactions...) if so, the answer is YES
Maybe that's the reason why heat death cannot happen. Our universe appears to be super-stable, both at the macroscopic and sub-atomic level. Maybe further understanding of the CMB would answer this question once and for all.
Not to sound ignorant, but what is a quantum fluctuation?
So in heat death, some virtual particles/bubbles could still become real for a quick instant?
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