- #1
lornstone
- 6
- 0
Hi,
In Mandl&Shaw, when we calculate the covaiant commutation relations for a scalar field we obtain :
[tex] [\phi(x),\phi(y)]= i\Delta(x-y)=0[/tex]
and the last equality stands if x-y is a space-like interval. But I don't understand why. We know that it is zero if the time component is zero and we also know that delta is invariant under proper Lorentz transformation. I don't see why we can't do the correct lorentz transformation (which bring time to zero) with a time-like interval so that it is also zero.
Thank you!
In Mandl&Shaw, when we calculate the covaiant commutation relations for a scalar field we obtain :
[tex] [\phi(x),\phi(y)]= i\Delta(x-y)=0[/tex]
and the last equality stands if x-y is a space-like interval. But I don't understand why. We know that it is zero if the time component is zero and we also know that delta is invariant under proper Lorentz transformation. I don't see why we can't do the correct lorentz transformation (which bring time to zero) with a time-like interval so that it is also zero.
Thank you!