Electric-magnetic duality rotations in non-linear electrodynamics Original Research Article

We show that there is a function of one variableʹs worth of Lagrangians for a single Maxwell field coupled to gravity whose equations of motion admit electric-magnetic duality. Such Lagrangians are given by solutions of the Hamilton-Jacobi equation for timelike geodesics in Wittenʹs two-dimensional black hole. Among them are the Born-Infeld Langrangian which arises in open string theory. We investigate the effect of the axion and the dilaton in the open superstring case and we show that this theory loses its electric-magnetic duality invariance when one considers the higher order electromagnetic field terms. We discuss some implications for black holes in string theory and an extension to 2k-forms in 4k spacetime dimensions.