SL(2,R) duality-symmetric action for electromagnetic theory with electric and magnetic sources

Abstract For the SL(2, R ) duality-invariant generalization of Maxwell electrodynamics in the presence of both electric and magnetic sources, we formulate a local, manifestly duality-symmetric, Zwanziger-type action by introducing a pair of four-potentials A μ and B μ in a judicious way. On the two potentials A μ and B μ the SL(2, R ) duality transformation acts in a simple linear manner. In quantum theory including charged source fields, this action can be recast as a SL(2, Z )-invariant action. Also given is a Zwanziger-type action for SL(2, R ) duality-invariant Born–Infeld electrodynamics which can be important for D-brane dynamics in string theory.