- #1
ehrenfest
- 2,020
- 1
Homework Statement
On page 221 Zwiebach uses the "definition" M^2 = -p^2. I am not sure where this comes from since normally
m^2c^4 + p^2 c^2 = E^2
and even dropping the c's does not reduce to that.
EDIT: I see. It is the light-cone Lorentz generator of section 11.6. How is he getting the square of it though? Working it out with 11.76?
EDIT 2: Wrong again. It is the just the energy-momentum invariant since the p I wrote above was only a three-vector. So, why is it a capital M?
Homework Equations
The Attempt at a Solution
Last edited: