Cosmology with Coupled Gravity and Dark Energy

TL;DR

The paper introduces a coupled gravity and dark energy (DEMC) model that aligns better with high-redshift universe expansion data than the standard LCDM model, potentially addressing several cosmological anomalies.

Contribution

It presents a novel DEMC cosmological model integrating dark energy and gravity in a unified framework with unique symmetry properties.

Findings

DEMC matches high-redshift expansion rate measurements better than LCDM.

The model predicts a slower expansion rate at high z consistent with observations.

DEMC offers explanations for large-scale CMB anomalies and quasar group structures.

Abstract

Dark energy is a fundamental constituent of our universe, its status in the cosmological field equation should be equivalent to that of gravity. Here we construct a dark energy and matter gravity coupling (DEMC) model of cosmology in a way that dark energy and gravity are introduced into the cosmological field equation in parallel with each other from the beginning. The DEMC universe possesses a composite symmetry from global Galileo invariance and local Lorentz invariance. The observed evolution of the universe expansion rate at redshift z>1 is in tension with the standard LCDM model, but can be well predicted by the DEMC model from measurements of only nearby epochs. The so far most precise measured expansion rate at high z is quite a bit slower than the expectations from LCDM, but remarkably consistent with that from DEMC. It is hoped that the DEMC scenario can also help to solve other existing challenges to cosmology: large scale anomalies in CMB maps and large structures up to about 10^3 Mpc of a quasar group. The DEMC universe is a well defined mechanical system. From measurements we can quantitatively evaluate its total rest energy, present absolute radius and expanding speed.