- #1
Dixanadu
- 254
- 2
Homework Statement
Hey guys!
So I have a Lagrangian with two coupled fields like so:
[itex] \mathcal{L} = \frac{1}{2}(\partial_{\mu}\phi_{1})(\partial^{\mu}\phi_{1}) +\frac{1}{2}(\partial_{\mu}\phi_{2})(\partial^{\mu}\phi_{2})-\frac{m_{1}^{2}}{2}(\phi_{1}\phi_{1})-\frac{m_{2}^{2}}{2}(\phi_{2}\phi_{2})-g(\phi_{1}\phi_{2})^2 [/itex]
where g is a coupling constant.
So I have to find the variation of this lagrangian under the transformation
[itex]\delta\phi_{1}=\epsilon\phi_{2}, \delta\phi_{2}=-\epsilon\phi_{1}[/itex]
Homework Equations
The Attempt at a Solution
I don't know what to do - do I just plug these into the Lagrangian? and if I do, how do I compute the new [itex]\partial_{\mu}\phi[/itex]?
Thanks a lot guys!