- #1
Dixanadu
- 250
- 2
Hey guys,
So I have a question about the gauge invariance of the weak field approximation. So if I write the approximation as
\Box h^{\mu\nu} -\partial_{\alpha}(\partial^{\mu}h^{\nu\alpha}+\partial^{\nu}h^{\mu\alpha})+\partial^{\mu}\partial^{\nu}h=0
then this is invariant under the gauge transformation
\delta h^{\mu\nu}=\partial^{\mu}\epsilon^{\nu}+\partial^{\nu}\epsilon^{\mu}+\mathcal{O}(\epsilon, h)
if you ignore the correction terms. So my question is...how does this variation come about? I mean how would I calculate this variation from first principles, using g^{\mu\nu}(x)=\eta^{\mu\nu}+h^{\mu\nu}(x)?
I looked at wikipedia and I didnt understand a word...so can someone please offer a simplified explanation of how to achieve this expression?
Thanks guys!
So I have a question about the gauge invariance of the weak field approximation. So if I write the approximation as
\Box h^{\mu\nu} -\partial_{\alpha}(\partial^{\mu}h^{\nu\alpha}+\partial^{\nu}h^{\mu\alpha})+\partial^{\mu}\partial^{\nu}h=0
then this is invariant under the gauge transformation
\delta h^{\mu\nu}=\partial^{\mu}\epsilon^{\nu}+\partial^{\nu}\epsilon^{\mu}+\mathcal{O}(\epsilon, h)
if you ignore the correction terms. So my question is...how does this variation come about? I mean how would I calculate this variation from first principles, using g^{\mu\nu}(x)=\eta^{\mu\nu}+h^{\mu\nu}(x)?
I looked at wikipedia and I didnt understand a word...so can someone please offer a simplified explanation of how to achieve this expression?
Thanks guys!