Possible Impact of non-Gaussianities on cosmological constraints in neutrino physics

Abstract

The search for non-Gaussian signatures in the Cosmic Microwave Background (CMB) is crucial for understanding the physics of the early Universe. Given the possibility of non-Gaussian fluctuations in the CMB, a recent revision to the standard $\Lambda$-Cold Dark Matter ($\Lambda$CDM) model has been proposed, dubbed "Super-$\Lambda$CDM". This model introduces additional free parameters to account for the potential effects of a trispectrum in the primordial fluctuations. In this study, we explore the impact of the Super-$\Lambda$CDM model on current constraints on neutrino physics. In agreement with previous research, our analysis reveals that for most of the datasets, the Super-$\Lambda$CDM parameter $A_0$ significantly deviates from zero at over a $95\%$ confidence level. We then demonstrate that this signal might influence current constraints in the neutrino sector. Specifically, we find that the current constraints on neutrino masses may be relaxed by over a factor of two within the Super-$\Lambda$CDM framework, thanks to the correlation present with $A_0$. Consequently, locking $A_0=0$ might introduce a bias, leading to overly stringent constraints on the total neutrino mass.