PT Journal AU Gavela, MB Lopez Honorez, L Mena, O Rigolin, S TI Dark coupling and gauge invariance SO Journal of Cosmology and Astroparticle Physics JI J. Cosmol. Astropart. Phys. PY 2010 BP 044 EP 15pp VL 11 IS 11 DI 10.1088/1475-7516/2010/11/044 LA English DE cosmological perturbation theory; dark energy theory; dark energy experiments ER