A Universe without expansion

TL;DR

This paper proposes a cosmological model where the universe contracts while particle masses grow exponentially, eliminating the big bang singularity and suggesting that observable ratios are due to shrinking atoms rather than expansion.

Contribution

It introduces a model with growing particle masses from a scalar field, challenging the traditional expansion paradigm and linking the big bang to coordinate choices.

Findings

Model is compatible with current observations.

Universe shows no big bang singularity in certain variables.

Alternative field coordinates reveal different universe behaviors.

Abstract

We discuss a cosmological model where the universe shrinks rather than expands during the radiation and matter dominated periods. Instead, the Planck mass and all particle masses grow exponentially, with the size of atoms shrinking correspondingly. Only dimensionless ratios as the distance between galaxies divided by the atom radius are observable. Then the cosmological increase of this ratio can also be attributed to shrinking atoms. We present a simple model where the masses of particles arise from a scalar "cosmon" field, similar to the Higgs scalar. The potential of the cosmon is responsible for inflation and the present dark energy. Our model is compatible with all present observations. While the value of the cosmon field increases, the curvature scalar is almost constant during all cosmological epochs. Cosmology has no big bang singularity. There exist other, equivalent choices of field variables for which the universe shows the usual expansion or is static during the radiation or matter dominated epochs. For those "field coordinates" the big bang is singular. Thus the big bang singularity turns out to be related to a singular choice of field coordinates.