- #1
nickyrtr
- 93
- 2
I am interested to know what Newton's second law (F=ma) looks like in general relativity. Looking at the geodesic equation, it appears to have some similarity. Multiply the mass of a particle by both sides and it looks like this:
[tex]m\frac{d^2x^{\mu}}{ds^2}+m\Gamma^{\mu}_{\nu\lambda}\frac{dx^{\nu}}{ds}\frac{dx^{\lambda}}{ds} = 0[/tex]
The left side resembles 'ma' in F=ma. The above describes a particle influenced only by gravity, so now I wonder how the equation changes when other forces are present, electromagnetism for example. From web searching and looking in textbooks I do not find any modified version of the geodesic equation that would fit, but there are some that look similar. This is my best guess, where q is the particle's charge and A is a potential due to some field:
[tex]m\frac{d^2x^{\mu}}{ds^2}+m\Gamma^{\mu}_{\nu\lambda}\frac{dx^{\nu}}{ds}\frac{dx^{\lambda}}{ds} = q\frac{dx^{\nu}}{ds}\frac{dA^{\mu}}{dx^{\nu}}[/tex]
Is this equation correct? It seems the right hand side is the GR analog to 'F' in F=ma. If anyone can refer me to a textbook or publication with this kind of equation, I would appreciate it very much.
[tex]m\frac{d^2x^{\mu}}{ds^2}+m\Gamma^{\mu}_{\nu\lambda}\frac{dx^{\nu}}{ds}\frac{dx^{\lambda}}{ds} = 0[/tex]
The left side resembles 'ma' in F=ma. The above describes a particle influenced only by gravity, so now I wonder how the equation changes when other forces are present, electromagnetism for example. From web searching and looking in textbooks I do not find any modified version of the geodesic equation that would fit, but there are some that look similar. This is my best guess, where q is the particle's charge and A is a potential due to some field:
[tex]m\frac{d^2x^{\mu}}{ds^2}+m\Gamma^{\mu}_{\nu\lambda}\frac{dx^{\nu}}{ds}\frac{dx^{\lambda}}{ds} = q\frac{dx^{\nu}}{ds}\frac{dA^{\mu}}{dx^{\nu}}[/tex]
Is this equation correct? It seems the right hand side is the GR analog to 'F' in F=ma. If anyone can refer me to a textbook or publication with this kind of equation, I would appreciate it very much.