Emergence of spacetime dynamics in entropy corrected and braneworld models

Abstract

A very interesting new proposal on the origin of the cosmic expansion wasrecently suggested by Padmanabhan [arXiv:1206.4916]. He argued that thedifference between the surface degrees of freedom and the bulk degrees offreedom in a region of space drives the accelerated expansion of theuniverse, as well as the standard Friedmann equation through relation △V = △t(Nsur−Nbulk). Inthis paper, we first present the general expression for the numberof degrees of freedom on the holographic surface,Nsur, using the general entropy corrected formulaS = A/(4Lp2)+s(A). Then, as two example, by applyingthe Padmanabhan's idea we extract the corresponding Friedmannequations in the presence of power-law and logarithmic correctionterms in the entropy. We also extend the study to RS II and DGPbraneworld models and derive successfully the correct form of theFriedmann equations in these theories. Our study further supportsthe viability of Padmanabhan's proposal.