SNe Ia Redshift in a Non-Adiabatic Universe

TL;DR

This paper proposes a non-adiabatic cosmological model that fits supernovae Ia redshift data better than the standard Lambda-CDM model using only the Hubble constant, suggesting a new interpretation of the cosmological constant.

Contribution

It introduces a non-adiabatic universe model that explains supernovae Ia data with fewer parameters than the standard model, offering a new perspective on the cosmological constant.

Findings

Better fit to supernovae Ia data with a single parameter

Hubble constant estimated at 68.28 km/s/Mpc

Deceleration parameter q_0 = -0.4

Abstract

By relaxing the constraint of adiabatic universe used in most cosmological models, we have shown that the new approach provides a better fit to the supernovae Ia redshift data with a single parameter, the Hubble constant $H_0$, than the standard $\Lambda$CDM model with two parameters, $H_0$ and the cosmological constant $\Lambda$ related density $\Omega_{\Lambda}$. The new approach is compliant with the cosmological principle. It yields the H_0=68.28 (+- 0.53) km s-1Mpc-1 with an analytical value of the deceleration parameter q_0=-0.4. The analysis presented is for a matter only, flat universe. The cosmological constant $\Lambda$ may thus be considered as a manifestation of a non-adiabatic universe that is treated as an adiabatic universe.