Emergence of Cosmic Space and the Generalized Holographic Equipartition

TL;DR

This paper extends Padmanabhan's idea that cosmic expansion results from the emergence of space, deriving generalized Friedmann equations for various gravity theories in higher dimensions.

Contribution

It generalizes the holographic equipartition principle to derive Friedmann equations in higher-dimensional gravity theories.

Findings

Derived Friedmann equations for Einstein, Gauss-Bonnet, and Lovelock gravities.

Unified the emergence of space concept across different gravity models.

Showed consistency with known cosmological equations.

Abstract

Recently, a novel idea about our expanding Universe was proposed by T. Padmanabhan [arXiv:1206.4916]. He suggested that the expansion of our Universe can be thought of as the emergence of space as cosmic time progresses. The emergence is governed by the basic relation that the increase rate of Hubble volume is linearly determined by the difference between the number of degrees of freedom on the horizon surface and the one in the bulk. In this paper, following this idea, we generalize the basic relation to derive the Friedmann equations of an $(n+1)$-dimensional Friedmann-Robertson-Walker universe corresponding to general relativity, Gauss-Bonnet gravity, and Lovelock gravity.