Simplicity in cosmology: add virialisation, remove $\Lambda$, keep classical GR

TL;DR

This paper proposes a simpler, physically motivated cosmological model within classical general relativity that accounts for observations without invoking dark energy or the cosmological constant.

Contribution

It introduces a general-relativistic cosmological model that includes virialisation effects and removes the need for a cosmological constant, challenging the standard $ ext{Lambda}$CDM paradigm.

Findings

Extragalactic observations can be modeled within classical GR without dark energy.

The proposed model fits supernovae distance-redshift data.

Preliminary checks suggest physical simplicity over $ ext{Lambda}$CDM.

Abstract

Present-day extragalactic observations are mostly rather well-modelled by a general-relativistic model, the $\Lambda$ CDM model. The model appears to surpass the limits of known physics by requiring that the Universe be dominated by "dark energy". However, the model sacrifices physical simplicity in favour of applied mathematical simplicity. A physically simpler, general-relativistic alternative to the $\Lambda$ CDM model is described here, along with preliminary observational checks. Thus, it will be argued that extragalactic observations such as the distance-modulus--redshift relation of type Ia supernovae are well-modelled within classical general relativity, without the addition of "new physics".