Year: 2014
Type: article
Abstract: We show that, in the presence of massive neutrinos, the Galileon gravity model provides a very good fit to the current cosmic microwave background (CMB) temperature, CMB lensing and baryonic acoustic oscillation data. This model, which we dub $\ensuremath{\nu}\text{Galileon}$, when assuming its stable attractor background solution, contains the same set of free parameters as lambda cold dark matter ($\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$), although it leads to different expansion dynamics and nontrivial gravitational interactions. The data provide compelling evidence ($\ensuremath{\gtrsim}6\ensuremath{\sigma}$) for nonzero neutrino masses, with $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}\ensuremath{\gtrsim}0.4\text{ }\text{ }\mathrm{eV}$ at the $2\ensuremath{\sigma}$ level. Upcoming precision terrestrial measurements of the absolute neutrino mass scale therefore have the potential to test this model. We show that CMB lensing measurements at multipoles $l\ensuremath{\lesssim}40$ will be able to discriminate between the $\ensuremath{\nu}\text{Galileon}$ and $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ models. Unlike $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$, the $\ensuremath{\nu}\text{Galileon}$ model is consistent with local determinations of the Hubble parameter. The presence of massive neutrinos lowers the value of ${\ensuremath{\sigma}}_{8}$ substantially, despite of the enhanced gravitational strength on large scales. Unlike $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$, the $\ensuremath{\nu}\text{Galileon}$ model predicts a negative ISW effect, which is difficult to reconcile with current observational limits.
Institution: Durham University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: Visiting Fellowships at Durham, G1381339075, Durham DiRAC-2 petascale facility, Visiting Fellowships at Durham, G1893551499, INVISIBLES, The formation of cosmic structure: 2008-2013, G4831232377, The Formation of Cosmic Structure: 2011-2016, G6583118092, USING THE LARGE-SCALE STRUCTURE OF THE UNIVERSE TO CHARACTERIZE DARK ENERGY, G7165083805, G7845306389, G8092745986, The Virgo consortium for cosmological supercomputer simulations, Durham DiRAC-2 petascale facility support
OpenAlex ID: W1503657109