The probability when the wave-function collapses

[thaiqi]

TL;DR

The projection postulate

Hello, everyone. The projection postulate says the wave-function collapses to one of its eigenstates under measurement, does it talk about each probability with which the wave-function collapses to those possible eigenstates?

 

[kith]

No, the probabilities for the different measurement outcomes are part of a another postulate which is called the Born rule.

 

[thaiqi]

No, the probabilities for the different measurement outcomes are part of a another postulate which is called the Born rule.

Thanks. So the Born rule and Born's $\psi$ interpretation are two different things?(Sorry I can't visit wiki )

 

[kith]

No, they are the same (or at least closely related).

 

[thaiqi]

No, they are the same (or at least closely related).

Why do you say they are the same? Born rule is for measurement, while the Born's $\psi$ interpretation is for the probability distribution in the space of particles(which has nothing to do with measurement). Shouldn't they have nothing to do with each other?

 

[kith]

Born rule is for measurement, while the Born's $\psi$ interpretation is for the probability distribution in the space of particles(which has nothing to do with measurement).

That's not correct. There isn't a probability distribution independent of measurements in QM. $|\psi(x)|^2$ being a probability density is just the Born rule in the special case of position being measured.

What is this thread about?

 

[thaiqi]

What is this thread about?

Sorry I don't understand this question.

 

[PeterDonis]

Sorry I don't understand this question.

His question means that we don't understand what your issue is.

 

[thaiqi]

His question means that we don't understand what your issue is.

Are there any exercises examples that use this projection postulate and need to use Born rule when computing?

 

[PeterDonis]

Are there any exercises examples that use this projection postulate and need to use Born rule when computing?

Have you tried looking in textbooks on QM? They have lots of exercises.

 

[thaiqi]

Have you tried looking in textbooks on QM? They have lots of exercises.

Thanks. I found two: Laloe's and Norsen's.
The other two maybe of help: Neumaier's and Nelson Bolivar's.
Also, Matteo Paris's article maybe is of help (The modern tools of quantum mechanics).

 

[PeterDonis]

I found two

Good, then go do the exercises in them. If you have questions about a particular exercise, you can start a new thread (in the homework forum, since that's where questions about textbook exercises should go).

This thread is closed.