# QM Phase & Four-Vectors

Gold Member

## Main Question or Discussion Point

The QM phase of a single particle traveling freely in 3 dimensions is (rp – Et), where r and p are the 3-D position and momentum vectors. This is also the dot product of the space-time four-vector (r,-t) with the Energy-Momentum four-vector (p,E)

Is this "coincidence" related to relativistic QM?

Last edited:

Related Quantum Physics News on Phys.org
clem
No. It is not a coincidence. It is the case in any relativistic wave, including classical EM.

Gold Member
No. It is not a coincidence. It is the case in any relativistic wave, including classical EM.
What classical EM equation(s) contain this term? I looked at the original version of Maxwell's Equations and could not see any connection. Thanks.

clem
A classical EM wave is $${\bf E}\exp[i({\bf k\cdot r}-\omega t)]$$.