Journal
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
Volume -, Issue 10, Pages -Publisher
IOP Publishing Ltd
DOI: 10.1088/1475-7516/2019/10/029
Keywords
cosmological parameters from LSS; cosmology of theories beyond the SM; baryon acoustic oscillations; big bang nucleosynthesis
Funding
- DFG [LE 3742/4-1, LE 3742/3-1]
- RWTH Aachen University [jara0184]
Ask authors/readers for more resources
Many attempts to solve the Hubble tension with extended cosmological models combine an enhanced relic radiation density, acting at the level of background cosmology, with new physical ingredients affecting the evolution of cosmological perturbations. Several authors have pointed out the ability of combined Baryon Acoustic Oscillation (BAO) and Big Bang Nucleosynthesis (BBN) data to probe the background cosmological history independently of both CMB maps and supernovae data. Using state-of-the-art assumptions on BBN, we confirm that combined BAO, deuterium, and helium data are in tension with the SH0ES measurements under the Lambda CDM assumption at the 3.2 sigma level, while being in close agreement with the CMB value. We subsequently show that floating the radiation density parameter N-eff only reduces the tension down to the 2.6 sigma level. This conclusion, totally independent of any CMB data, shows that a high N-eff accounting for extra relics (either free-streaming or self-interacting) does not provide an obvious solution to the crisis, not even at the level of background cosmology. To circumvent this strong bound, (i) the extra radiation has to be generated after BBN to avoid helium bounds, and (ii) additional ingredients have to be invoked at the level of perturbations to reconcile this extra radiation with CMB and LSS data.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available