<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>Q</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math> gravity and neutrino physics
Luís Atayde, Noemi Frusciante
Abstract
Within the $f(Q)$-gravity framework we perform a phenomenological study of the cosmological observables in light of the degeneracy between neutrinos physics and the modified gravity parameter and we identify specific patterns which allow to break such degeneracy. We also provide separately constraints on the total mass of the neutrinos, $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}$, and on the effective number of neutrino species, ${N}_{\mathrm{eff}}$, using cosmic microwave background (CMB), baryon acoustic oscillation (BAO), redshift space distortion (RSD), supernovae (SNIa), galaxy clustering (GC) and weak gravitational lensing (WL) measurements. The strongest upper bound on the total mass of the neutrinos is found for the combination of $\mathrm{CMB}+\mathrm{BAO}+\mathrm{RSD}+\mathrm{SNIa}$ and it is $\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}<0.277\text{ }\text{ }\mathrm{eV}$ at 95% C.L. For the same combination of data we find ${N}_{\mathrm{eff}}={2.93}_{\ensuremath{-}0.34}^{+0.31}$ at 95% C.L. We also find that all combinations of data we consider, prefer a stronger gravitational interaction than $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$. Finally, we consider the ${\ensuremath{\chi}}^{2}$ and deviance information criterion statistics and find the $f(Q)+\mathrm{\ensuremath{\Sigma}}{m}_{\ensuremath{\nu}}$ model to be statistically supported by data over the standard scenario. On the contrary $f(Q)+{N}_{\mathrm{eff}}$ is supported by $\mathrm{CMB}+\mathrm{BAO}+\mathrm{RSD}+\mathrm{SNIa}$ but a moderate evidence against it is found with GC and WL data.