1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Relativistic Invariance

  1. Oct 10, 2007 #1
    1. The problem statement, all variables and given/known data
    Prove that the quantity [itex]2EN^2 dx^3[/itex] is a relativistic invariant.

    2. Relevant equations

    Well we want to prove that this quantity is the same in all inercial frames.
    My doubt is with the energy transformation,

    [tex]E=\gamma E_0[/tex]

    does it transforms like that? If yes,


    [tex]2EN^2 dx^3=2 \gamma E_0 N^2 \frac{dx^3}{\gamma}=2E_0 N^2 dx_0^3[/tex]

    and its done...?

    Last edited: Oct 10, 2007
  2. jcsd
  3. Oct 11, 2007 #2


    User Avatar
    Science Advisor
    Homework Helper

    Do you know the covariant formalism ? If you do, you might know that [tex]p_{\mu}x^{\mu} [/tex] is a Lorentz scalar. Assume a Lorentz boost in the positive Ox direction...Can you continue from here ?

    P.S. What does N stand for ?
  4. Oct 12, 2007 #3
    I have done it. That result is correct. Thanks a lot.
    By the way N stands for a normalization factor that cames, I guess, from the wave function.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook