Probing Self-Interacting Neutrinos with Cosmological Data - David Camarena (New Mexico U.)

Abstract: According to several analyses, a cosmological scenario in which neutrinos strongly interact among themselves, delaying their free-streaming until close to the epoch of matter-radiation equality, provides a good fit for some cosmic microwave background (CMB) data, while being somewhat disfavored by Planck CMB polarization data. To clarify this situation, we recently investigated, in a CMB-independent way, the compatibility of the self-interacting neutrinos with the Full Shape of the galaxy power spectrum. Interestingly, our analyses revealed that the large-scale distribution of galaxies allows for a cosmological scenario in which neutrinos strongly interact among themselves. This non-trivial agreement between the LSS and CMB data motivates the exploration of particle models capable of reconciling all CMB, large-scale structure, and laboratory data.