A Case for an Inhomogeneous Einstein-de Sitter Universe

TL;DR

This paper proposes an inhomogeneous Einstein-de Sitter universe model where cosmic acceleration arises from structure formation, fitting observational data without dark energy and addressing the Hubble tension.

Contribution

It introduces a local-to-global cosmological framework with inhomogeneities causing acceleration, challenging the need for dark energy in explaining cosmic expansion.

Findings

Fits CMB, BAO, and SN Ia data comparably to ΛCDM.

Resolves the H_0 tension.

Predicts a cosmic age of about 13.67 Gyr.

Abstract

We present a local-to-global cosmological framework in which cosmic acceleration emerges from structure formation in an inhomogeneous Einstein-de Sitter (iEdS) universe, without dark energy. The model exhibits a quasilinear coasting evolution toward an effective Milne state driven by growing inhomogeneities. We test the iEdS model with ${H_0=72.5\ \mathrm{km\ s^{-1}\ Mpc^{-1}}}$ and ${\Omega_{\mathrm{m},0}=0.272}$ using CMB, BAO, and SN Ia data. The iEdS model fits the data comparably to $\Lambda$CDM and resolves the $H_0$ tension, while yielding a cosmic age ${t_0\simeq 13.67\ \mathrm{Gyr}}$ consistent with globular-cluster estimates.