This question already has an answer here:
can anyone explain what is mentioned here https://arxiv.org/abs/1405.6091 (page 7 and 8) in simple terms: Finally, Krauss makes the very problematic claim that
“the structures we can see, like stars and galaxies, were all created by quantum fluctuations from nothing” .
The issue that is not being addressed here is the fundamental transition problem of going from a pure quantum state to a classical state. The reason for this is first and foremost due to the problem of quantization, which in its general form, is seldom addressed in even advanced physics textbooks on quantum mechanics .