Observational constraints on the massive neutrinos induced late-time cosmic acceleration

TL;DR

This paper explores a model where a scalar field coupled to massive neutrinos can mimic dark energy, with observational data constraining the late-time cosmic acceleration driven by neutrino interactions.

Contribution

It introduces a conformally coupled scalar field model with spontaneous symmetry breaking that can replicate dark energy behavior, constrained by observational data.

Findings

Neutrino coupling can produce late-time cosmic acceleration.

Model behaves like a weakly dynamical dark energy.

Lambda-CDM is recovered as a limiting case.

Abstract

We study a scenario based upon a mass-less $\lambda \phi^4$ theory coupled to massive neutrino matter with $Z_2$ symmetry using a conformal coupling, $A(\phi)=1-\alpha\phi^2/2M_{pl}^2;~\alpha=M^2_{pl}/M^2$ where $M$ is a cut off mass. The chosen coupling generically leads to the spontaneous symmetry breaking at late times such that the field acquires non-zero mass, $m_\phi=(\alpha \Omega_{0\nu})^{1/2}H_0 \ll H_0 $ and rolls slowly around the true ground state which emerges after spontaneous symmetry breaking. For the statistical analysis, we utilize Pantheon+Multi-Cycle Treasury and OHD data sets. We find that even a small fraction of the neutrino matter density together with its coupling to the scalar field can actually make our model to behave like a weakly dynamical dark energy and have $\Lambda$CDM model as a limiting case.