Flat limits of curved interacting cosmic fluids

TL;DR

This paper investigates curved cosmological models with two interacting fluids and finds that many asymptote to flat universe behavior near singularities, with implications for cosmic no hair conjectures and quantum cosmology.

Contribution

It demonstrates that certain curved interacting fluid cosmologies approach flat limits near singularities, extending understanding of cosmic behavior and potential quantum implications.

Findings

Many curved models asymptote to flat universes near singularities

No essential singularities are present in these models

Links to quantum cosmology and cosmic no hair theorem extensions

Abstract

We study curved isotropic cosmologies filled with two interacting fluids near their time singularities. We find that a number of these universes asymptote to flat limits in the sense that their asymptotic properties become indistinguishable from those of flat Friedmann-Robertson-Walker models on approach to the singularity along any asymptotic direction. In particular, there are no essential singularities in these models. We discuss connections of this result with possible extensions of the cosmic no hair theorem to the case of two interacting fluids, and also provide links to a quantum cosmological treatment of real and complex Euclidean such solutions.