Symplectic structure of electromagnetic duality

We develop an electromagnetic symplectic structure on the space-time manifold by defining a Poisson bracket in terms of an invertible electromagnetic tensor F_{\mu\nu}. Moreover, we define electromagnetic symplectic diffeomorphisms by imposing a special condition on the electromagnetic tensor. This condition implies a special constraint on the Levi-Civita tensor. Then, we express geometrically the electromagnetic duality by defing a dual local coordinates system.