{\Lambda}CDM cosmology from visible matter only

TL;DR

This paper presents a Machian model of the universe that explains the b3CDM cosmology using only visible matter, deriving key parameters without dark energy or dark matter.

Contribution

It introduces a Machian framework deriving b3CDM parameters solely from visible matter, challenging the need for dark components in cosmology.

Findings

Derives Friedmann equation from Machian energy principles.

Shows b3CDM density parameters emerge naturally from visible matter.

Predicts a constant deceleration parameter q=-1/2 without dark energy.

Abstract

We discuss physical interpretation of {\Lambda}CDM cosmology from a Machian model of the universe containing nothing but visible matter (ordinary matter, radiation). The Friedmann equation can be derived from a Machian definition of energy, whereby both kinetic and potential energy of a particle are related to all cosmic matter-energy within the particle's gravitational horizon. The distance to this horizon thus appears as a parameter in all forms of matter-energy density. From conservation of Machian energy it follows that all different types of matter-energy are uniformly characterized by \rho\propto 1/a, i.e., by a constant deceleration q=-1/2. This coincides with relative densities \varOmega_{m}=1/3 and \Omega_{\Lambda}=2/3 of {\Lambda}CDM. Thus the Machian cosmological model matches present relative densities of {\Lambda}CDM, without invoking dark components.