# Cosmic structure sizes in generic dark energy models

Research paper by Sourav Bhattacharya, Theodore N Tomaras

Indexed on: 21 Mar '17Published on: 21 Mar '17Published in: arXiv - General Relativity and Quantum Cosmology

#### Abstract

The maximum allowable size of a spherical cosmic structure as a function of its mass is determined by the maximum turn around radius $R_{\rm TA,max}$, the distance from its center where the attraction on a test particle due to the spherical mass is balanced with the repulsion due to the ambient dark energy. $R_{\rm TA,max}$ is computed in the framework of several gravity models. (a) In the generic dark energy model with arbitrary time dependent state parameter $w(t)$, taking into account the effect of inhomogeneities upon the dark energy, where it is shown that the data constrain $w(t={\rm today})>-2.3$, and (b) in the quintessence and the generalized Chaplygin gas models, both of which are shown to predict structure sizes consistent with observations for all values of their parameters.