Vacuum polarization in d+12 dimensions

We study the main properties of the one-loop vacuum polarization function (Παβ) for spinor QED in 'd+12 dimensions', i.e., with fields defined on M⊂Rd+1 such that M={(x0,…,xd)|xd⩾0}, with bag-like boundary conditions on the boundary ∂M={(x0,…,xd)|xd=0}. We obtain an exact expression for the induced current due to an external constant electric field normal to the boundary. We show that, for the particular case of 2+1 dimensions, there is a transverse component for the induced current, which is localized on a region close to ∂M. This current is a parity breaking effect purely due to the boundary.