# Probability of an observable

1. Apr 23, 2012

Hey,

How would you compute the probability of measuring a specific value of an observable (resp. range for continuous variables), given a wavefunction with an eigenbasis that is different from the one associated with the observable?

An example: Let's consider my wave function is a superposition of energy-eigenfunctions, how would I get the probability of finding the momentum in a range [a,b]?

Best

2. Apr 23, 2012

### Matterwave

1) Obtain the momentum representation wave function.

2) Integrate its absolute square over the appropriate interval.