Hello,(adsbygoogle = window.adsbygoogle || []).push({});

Say I have a system with a spatial part and a spin degree of freedom, hence the wavefunction generally looks like [itex]\psi_+(\textbf r) |+\rangle + \psi_-(\textbf r) |- \rangle[/itex] w.r.t. for example the z-axis.

Now what if I'm simply interested in the spatial part? Can I perform an operation on this wavefunction such that I get a new wavefunction that is only spatial, but gives the same predictions for any observable that only depends on space variables? (e.g. [itex]L_z[/itex])

I feel this must be possible, and that it shouldn't even be hard, but I can't seem to think of the appriopriate operation right away and I also can't google it because I don't know what such an operation would be called.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# How can I ignore information in my wave function?

**Physics Forums | Science Articles, Homework Help, Discussion**