Hiding neutrino mass in modified gravity cosmologies

Understand

Cosmological observables show a dependence with the neutrino mass, which is partially degenerate with parameters of extended models of gravity.

• We study and explore this degeneracy in Horndeski generalized scalar-tensor theories of gravity.
• Using forecasted cosmic microwave background and galaxy power spectrum datasets, we find that a single parameter in the linear regime of the effective theory dominates the correlation with the total neutrino mass.
• For any given mass, a particular value of this parameter approximately cancels the power suppression due to the neutrino mass at a given redshift.