We investigate the impact of a nonstandard time evolution of the dark matter component on current cosmological bounds from cosmic microwave background (CMB) anisotropies. We found that a less than 0.1% variation in the effective dark matter equation of state w(dm) can drastically change current CMB bounds on the matter density, the Hubble parameter and the age of the Universe. A flat universe without dark energy could provide an excellent fit to current CMB data, providing that w(dm) similar to -10(-2).
Calabrese, E., Migliaccio, M., Pagano, L., De Troia, G., Melchiorri, A., Ro, ., et al. (2009). Cosmological constraints on the matter equation of state. PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY, 80(6) [10.1103/PhysRevD.80.063539].
Cosmological constraints on the matter equation of state
Migliaccio, Marina;De Troia, Grazia;Natoli, Paolo
2009-01-01
Abstract
We investigate the impact of a nonstandard time evolution of the dark matter component on current cosmological bounds from cosmic microwave background (CMB) anisotropies. We found that a less than 0.1% variation in the effective dark matter equation of state w(dm) can drastically change current CMB bounds on the matter density, the Hubble parameter and the age of the Universe. A flat universe without dark energy could provide an excellent fit to current CMB data, providing that w(dm) similar to -10(-2).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.