A Globally Unevolving Universe

TL;DR

This paper proposes a scalar-tensor gravity model with variable G and particle masses that describes a static universe, explaining cosmological observations without expansion and addressing key cosmological problems.

Contribution

It introduces a static cosmological model based on scalar-tensor gravity where G and masses vary, eliminating the need for universe expansion and solving major cosmological issues.

Findings

Dark energy density is twice that of matter, matching observations.

The model naturally explains CMB features like spectral flatness and Gaussian perturbations.

Many cosmological observations may have a kinematic origin rather than dynamic.

Abstract

A scalar-tensor theory of gravity is formulated in which $G$ and particle masses are allowed to vary. The theory yields a globally static cosmological model with no evolutionary timescales, no cosmological coincidences, and no flatness and horizon `problems'. It can be shown that the energy densities of dark energy ($\rho_{DE}$) and non-relativistic baryons and dark matter ($\rho_{M}$) are related by $\rho_{DE}=2\rho_{M}$, in agreement with current observations, if DE is associated with the canonical kinetic and potential energy densities of the scalar fields. Under general assumptions, the model favors light fermionic dark matter candidates (e.g., sterile neutrinos). The main observed features of the CMB are naturally explained in this model, including the spectral flatness of its perturbations on the largest angular scales, and the observed adiabatic and gaussian nature of density perturbations. More generally, we show that many of the cosmological observables, normally attributed to the dynamics of expanding space, could be of kinematic origin. In gravitationally bound systems, the values of G and particle masses spontaneously freeze out by a symmetry breaking of the underlying conformal symmetry, and the theory reduces to standard general relativity (with, e.g., all solar system tests satisfied).