2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/9209The cosmological (upper) limit on the Peccei-Quinn constant, related to the primordial oscillations of the axion field, can be relaxed for a mirror axion model. The simple reason is that the mirror world is colder and so the behavior of the axion temperature-dependent mass is dominated by the contribution from the mirror sector. So the coherent oscillations start earlier and correspondingly the axion mass density Ω_a h^2 is reduced.VI Friedmann Seminar, France, Corsica, Cargese, 2004, LaTeX, 5 pages. To be published in Int. J. Mod. Phys. AAstrophysicstext