de Broglie-Proca and Bopp-Podolsky massive photon gases in cosmology R. R. Cuzinatto, E. M. de Morais, L. G. Medeiros, C. Naldoni de Souza and B. M. Pimentel EPL, 118 1 (2017) 19001 Published online: 07 June 2017 DOI: 10.1209/0295-5075/118/19001