TY  - JOUR
AU  - Gariazzo, S.
AU  - Mena, O.
AU  - Ramirez, H.
AU  - Boubekeur, L.
PY  - 2017
DA  - 2017//
TI  - Primordial power spectrum features in phenomenological descriptions of inflation
T2  - Phys. Dark Universe
JO  - Physics of the Dark Universe
SP  - 38
EP  - 45
VL  - 17
PB  - Elsevier Science Bv
KW  - Inflation
KW  - Primordial power spectrum
KW  - Sound speed
AB  - We extend an alternative, phenomenological approach to inflation by means of an equation of state and a sound speed, both of them functions of the number of e-folds and four phenomenological parameters. This approach captures a number of possible inflationary models, including those with non-canonical kinetic terms or scale-dependent non-gaussianities. We perform Markov Chain Monte Carlo analyses using the latest cosmological publicly available measurements, which include Cosmic Microwave Background (CMB) data from the Planck satellite. Within this parameterization, we discard scale invariance with a significance of about 10 sigma, and the running of the spectral index is constrained as alpha(s) = -0.60(-0.10)(+0.08) x 10(-3) (68% CL errors). The limit on the tensor-to-scalar ratio is r < 0.005 at 95% CL from CMB data alone. We find no significant evidence for this alternative parameterization with present cosmological observations. The maximum amplitude of the equilateral non-gaussianity that we obtain, vertical bar f(NL)(equil)vertical bar < 1, is much smaller than the current Planck mission errors, strengthening the case for future high-redshift, all-sky surveys, which could reach the required accuracy on equilateral non-gaussianities.
SN  - 2212-6864
UR  - http://arxiv.org/abs/1606.00842
UR  - https://doi.org/10.1016/j.dark.2017.07.003
DO  - 10.1016/j.dark.2017.07.003
LA  - English
N1  - WOS:000411869100006
ID  - Gariazzo_etal2017
ER  -