Searching for a matter bounce cosmology with low redshift observations

TL;DR

This paper explores how low redshift observations can test matter bounce cosmologies, which predict specific signatures in cosmic microwave background and late-time universe data, potentially distinguishing them from standard cosmology.

Contribution

It demonstrates that low redshift data can provide evidence for matter bounce models and shows how dark matter-dark energy interactions can produce observable effects consistent with CMB observations.

Findings

Low redshift observations can test matter bounce scenarios.

Dark matter-dark energy interactions can generate a red tilt in primordial perturbations.

Potential deviations from ΛCDM may be explained by bouncing cosmologies.

Abstract

The matter bounce scenario allows for a sizable parameter space where cosmological fluctuations originally exited the Hubble radius when the background energy density was small. In this scenario and its extended versions, the low energy degrees of freedom are likely responsible for the statistical properties of the cosmic microwave background power spectrum at large length scales. An interesting consequence is that these modes might be observable only at relatively late times. Therefore low redshift observations could provide evidence for, or even falsify, various bouncing models. We provide an example where a recently hinted potential deviation from $\Lambda$-cold-dark-matter cosmology results from a dark matter and dark energy interaction. The same interaction allows matter bounce models to generate a red tilt for the primordial curvature perturbations in corroboration with cosmic microwave background experiments.