- I'm wondering if the "measurement postulate" and the "von Neumann’s projection postulate" refer to the same concept?
I find in the literature frequent reference to the "measurement postulate" and, sometimes, to the "von Neumann’s projection postulate". The difference, if any, seems to me subtle but I can't tell which. However, they are never mentioned both in the same context/paper, so I'm afraid that they may be two completely different postulates not to be confused. I don't get what the difference is. So, the question is if they are synonymous (in that case a simple "yes" answer is sufficient) or , if not, what distinguishes it?