- #1
rwooduk
- 762
- 59
In our particle physics lecture this term comes up often, it doesn't look right to me but the lecturer uses it so it must be:
##{\partial }^{2}A^{\mu} = - {\partial }_{\mu}{\partial }^{\mu}A^{\mu}+ {\partial }_{\mu}{\partial }^{2}A^{\mu}##
I understand if you have:
##F^{\mu v} = {\partial }_{\mu}A^{v} - {\partial }_{v}A^{\mu}##
then
##{\partial }_{\mu}F^{\mu v} = - {\partial }_{\mu}{\partial }^{\mu}A^{\mu}+ {\partial }_{\mu}{\partial }^{2}A^{\mu}##
but I don't understand how a term with a single indices can give the same? How would you derive the first equation? I've tried chain rule but there seems to be an extra delta in there. Any ideas would be really appreciated.
##{\partial }^{2}A^{\mu} = - {\partial }_{\mu}{\partial }^{\mu}A^{\mu}+ {\partial }_{\mu}{\partial }^{2}A^{\mu}##
I understand if you have:
##F^{\mu v} = {\partial }_{\mu}A^{v} - {\partial }_{v}A^{\mu}##
then
##{\partial }_{\mu}F^{\mu v} = - {\partial }_{\mu}{\partial }^{\mu}A^{\mu}+ {\partial }_{\mu}{\partial }^{2}A^{\mu}##
but I don't understand how a term with a single indices can give the same? How would you derive the first equation? I've tried chain rule but there seems to be an extra delta in there. Any ideas would be really appreciated.