Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Help to understand the Retarded Function

  1. Nov 26, 2016 #1
    Hi people, help here please
    When the Einstein equation are linearized the results are the weak field Einstein equations

    \left ( -\frac{\partial^{2}}{\partial t^{2}} + \nabla^{2} \right ) \bar h^{\mu\nu}=-16\pi T^{\mu\nu}
    a solution for this equations considering the source are the Retarded function
    \bar h^{\mu\nu} (t,\vec x)=4 \int d^{3}x' \frac{[T^{\mu\nu}(t',\vec x')]_{[ret]}}{|\vec x - \vec x'|}

    $$t' = t_{ret} = t-|\vec x - \vec x'|$$

    until i know "t" and "x" in spacetime are the same but what physical situation describes
    |\vec x - \vec x'|
    Is similar to electromagnestism, when $$\vec x$$ represent the place where you want calculate the potencial and $$\vec x'$$ represent the place where the charge is located?

    Thanks in advance
    Last edited by a moderator: Nov 26, 2016
  2. jcsd
  3. Nov 26, 2016 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    Your weak field equation is just a separate wave equation for every individual component. The solution is just applying the retarded Green's function of the wave equation.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted