Generalized Chaplygin gas model, supernovae and cosmic topology

TL;DR

This paper investigates how understanding the universe's spatial topology can constrain the parameters of the generalized Chaplygin gas model, which unifies dark energy and dark matter, using supernova data.

Contribution

It demonstrates that spatial topology knowledge adds constraints on the GCG model's $A_s$ parameter but does not resolve degeneracies in the $lpha$ parameter.

Findings

Topology constrains $A_s$ parameter of GCG.

Topology does not resolve $lpha$ degeneracy.

Supernova data combined with topology provides tighter constraints.

Abstract

In this work we study to which extent the knowledge of spatial topology may place constraints on the parameters of the generalized Chaplygin gas (GCG) model for unification of dark energy and dark matter. By using both the Poincar\'e dodecahedral and binary octahedral spaces as the observable spatial topologies, we examine the current type Ia supernovae (SNe Ia) constraints on the GCG model parameters. We show that the knowledge of spatial topology does provide additional constraints on the $A_s$ parameter of the GCG model but does not lift the degeneracy of the $\alpha$ parameter.