Friedmann equations from emergence of cosmic space

TL;DR

This paper extends Padmanabhan's emergence of spacetime framework to derive Friedmann equations for nonflat universes across various gravity theories, including higher dimensions, Gauss-Bonnet, and Lovelock gravity.

Contribution

It provides the first derivation of Friedmann equations in nonflat FRW universes within Gauss-Bonnet and Lovelock gravity using the emergence approach.

Findings

Derived Friedmann equations for nonflat universes in Einstein, Gauss-Bonnet, and Lovelock gravity.

Extended the emergence framework to higher-dimensional spacetimes.

Supported the viability of Padmanabhan's emergence perspective on gravity.

Abstract

Padmanabhan [arXiv:1206.4916] argues that the cosmic acceleration can be understood from the perspective that spacetime dynamics is an emergence phenomena. By calculating the difference between the surface degrees of freedom and the bulk degrees of freedom in a region of space, he also arrives at the Friedmann equation in a flat universe. In this paper, by modification of his proposal, we are able to derive the Friedmann equation of the Friedmann-Robertson-Walker universewith any spatial curvature.We also extend the study to higher-dimensional spacetime and derive successfully the Friedmann equations not only in Einstein gravity but also in Gauss-Bonnet and more general Lovelock gravity with any spatial curvature. This is the first derivation of Friedmann equations in these gravity theories in a nonflat Friedmann-Robertson-Walker universe by using the novel idea proposed by Padmanabhan. Our study indicates that the approach presented here is powerful enough and further supports the viability of Padmanabhan's perspective of emergence gravity.