# Prove that TDSE is invariant under Galilean Transformation.

I want the proof for a general wavefunction Ψ(x,t).

rubi
The Schrödinger equation isn't invariant under Galilean transformations. It's invariant under a central extension of the universal cover of the Galilean group. Specifically, this means that you cannot just apply a Galilean transformation to the wave-function, but you need to add a (mass and time dependent) phase factor in order to transform a solution into another solution. In contrast to the Lorentz group, the phase factor cannot be made to vanish in case of the Galilean group.

PeterDonis
Mentor
2020 Award
I want the proof for a general wavefunction Ψ(x,t).
A proof of what?

A proof of what?
I want to prove that the time dependent Schrödinger equation is invariant under Galilean transformation.

bhobba
Mentor
I want to prove that the time dependent Schrödinger equation is invariant under Galilean transformation.
See chapter 3 Ballentine - QM - A Modern Development - he does the converse - proves the Schrodinger equation from the Galilean principle of relativity. Specifically he assumes the probabilities of an observation are invariant.

BTW I think Rubi is right although I haven't gone deep into it.

Had a quick scan through Ballentine and Rubi is correct. Here is a paper I found on it - note the phase change mentioned by Rubi.

It says it is invariant - but with that phase change things are a bit murkier. Interesting question - before going into it I would have said yes it is - however its a bit more subtle.

Thanks
Bill

Last edited:
Viraj Daniel Dsouza
hilbert2
Gold Member
Could this be somehow deduced from the fact that the canonical commutation relation ##[\hat{x},\hat{p}]=i\hbar## doesn't change in the transformation

##\hat{x} \rightarrow \hat{x}+vt##,
##\hat{p} \rightarrow \hat{p} + mv##

with ##m## and ##v## real numbers and ##t## the time?

On the other hand, the commutator at any time ##t## will also remain the same if the ##vt## is replaced by ##\beta t^2## or something else that is nonlinear in ##t##.