Evolution of gravity-dark energy coupled expanding universe

TL;DR

This paper develops a dynamic model of the universe's evolution considering gravity-dark energy coupling, aligning with observations and predicting a three-epoch cosmic history with future observational implications.

Contribution

It introduces a new dynamic equation for universe evolution incorporating gravity-dark energy coupling, providing a novel explanation consistent with current data.

Findings

Universe experienced an equilibrium epoch at z>1

A phase transition occurred between z~0.5 and 1

Current acceleration began at z~0.5

Abstract

The acceleration of the cosmic expansion revealed by supernova observations indicates that the present universe is dominated by repulsive dark energy. It is natural that the coupling between the dark energy and the attractive gravity has to be taken into account in studying the evolution of our universe. Here we induce a dynamic equation of universe evolution based on the cosmological principal, gravity-dark energy coupling, and energy conservation. The solutions of this dynamic equation provide a specific picture of cosmic evolution, which is well compatible with current observed evolution histories of both Hubble parameter H(z) and equation of state parameter w(z) of dark energy. In this picture, the already observed universe has undergone through three epochs - the epoch of equilibrium between gravity and dark energy at cosmological redshifts z>1, the phase transition epoch at z between about 0.5 and 1, and the present acceleration epoch starting from z~0.5. The expected matter-dominated deceleration epoch has not been seen yet, which requires future deep observations to look back upon more early universe.