A 3-form gauge potential in 5D in connection with a possible dark sector of 4D-electrodynamics D. Cocuroci, M. J. Neves, J. A. Helayël-Neto and L. P. R. Ospedal Eur. Phys. J. C, 75 7 (2015) 322 Published online: 11 July 2015 DOI: 10.1140/epjc/s10052-015-3540-4