TY  - JOUR
AU  - Giare, W.
AU  - Renzi, F.
AU  - Mena, O.
AU  - Di Valentino, E.
AU  - Melchiorri, A.
PY  - 2023
DA  - 2023//
TI  - Is the Harrison-Zel'dovich spectrum coming back? ACT preference for n(s) similar to 1 and its discordance with Planck
T2  - Mon. Not. Roy. Astron. Soc.
JO  - Monthly Notices of the Royal Astronomical Society
SP  - 2911
EP  - 2918
VL  - 521
IS  - 2
PB  - Oxford Univ Press
KW  - cosmological parameters
KW  - inflation
KW  - cosmology: observations
KW  - cosmology: theory
AB  - The Data Release 4 of the Atacama Cosmology Telescope (ACT) shows an agreement with an Harrison-Zel'dovich primordial spectrum (n(s) = 1.009 +/- 0.015), introducing a tension with a significance of 99.3 per cent Confidence Level (CL) with the results from the Planck satellite. The discrepancy on the value of the scalar spectral index is neither alleviated with the addition of large scale structure information nor with the low multipole polarization data. We discuss possible avenues to alleviate the tension relying on either neglecting polarization measurements from ACT or in extending different sectors of the theory.
SN  - 0035-8711
UR  - https://arxiv.org/abs/2210.09018
UR  - https://doi.org/10.1093/mnras/stad724
DO  - 10.1093/mnras/stad724
LA  - English
N1  - WOS:000957248500013
ID  - Giare_etal2023
ER  -