Cosmology with Type II Supernovae

TL;DR

This study uses Type II supernovae data combined with other cosmological observations to test for physics beyond the standard $\\Lambda$CDM model, finding consistency with current models but emphasizing the need for larger samples for definitive conclusions.

Contribution

It provides the first comprehensive constraints on multiple alternative cosmological models using Type II supernovae data combined with other observations.

Findings

Spatially flat universe supported in non-flat $\Lambda$CDM model

Dark energy equation of state consistent with $\Lambda$CDM

No evidence for interaction in the dark sector

Abstract

With the recent progresses on the Type II supernovae, we attempt to investigate whether there does exist new physics beyond the standard cosmological paradigm, i.e., the cosmological constant $\Lambda$ plus cold dark matter ($\Lambda$CDM). Constraining four alternative cosmological models with a data combination of currently available Type II supernovae calibrated by the standard color method, Type Ia supernovae, baryon acoustic oscillations, cosmic microwave background and cosmic chronometers, at the $1\sigma$ confidence level, we find that: (i) a spatially flat universe is supported for the non-flat $\Lambda$CDM model; (ii) the constrained equation of state of dark energy $\omega$ is consistent with the $\Lambda$CDM hypothesis for the $\omega$CDM model where $\omega$ is a free parameter; (iii) for the decaying vacuum model, there is no evidence of interaction between dark matter and dark energy in the dark sector of the universe; (iv) there is also no hint of dynamical dark energy for the dark energy density-parametrization scenario. It is very obvious that a larger Type II supernovae sample is required, if we expect to draw definitive conclusions about the formation and evolution of the universe.