Gravitational energy as dark energy: Average observational quantities

TL;DR

This paper explores how gravitational energy gradients in the timescape cosmological model can mimic dark energy effects, proposing observational tests to differentiate it from the cosmological constant.

Contribution

It introduces methods to define observational tests for average geometric quantities that distinguish the timescape model from dark energy or a cosmological constant.

Findings

Gravitational energy gradients can produce apparent cosmic acceleration.

Proposes observational tests to differentiate timescape from dark energy models.

Highlights the importance of average geometric quantities in cosmological observations.

Abstract

In the timescape scenario cosmic acceleration is understand as an apparent effect, due to gravitational energy gradients that grow when spatial curvature gradients become significant with the nonlinear growth of cosmic structure. This affects the calibratation of local geometry to the solutions of the volume-average evolution equations corrected by backreaction. In this paper I discuss recent work on defining observational tests for average geometric quantities which can distinguish the timescape model from a cosmological constant or other models of dark energy.