# EM Lagrangian

1. Jan 25, 2008

We have a suggested Lagrangian

epsilon(abcd) F^(ab) F^(cd)

and are asked to comment if this is a sensible EM Lagrangian. The only thing i can think of is that its still gauge invariant in the normal way but otherwise im stumped. would appreciate any suggestions. thanks

2. Jan 25, 2008

### dextercioby

Did you compute its field equations ?