Momentum transfer models of interacting dark energy

TL;DR

This paper investigates two models of interacting dark energy through momentum exchange, comparing their fit to cosmological data against standard models, and finds they can outperform $ ext{Lambda}$CDM in some cases.

Contribution

It introduces and tests two novel momentum exchange dark energy models, one phenomenological and one based on a Lagrangian formalism, against observational data.

Findings

Models are competitive with $ ext{Lambda}$CDM.

Some models fit data better with certain datasets.

Interacting dark energy models can outperform standard cosmology.

Abstract

We consider two models of interacting dark energy, both of which interact only through momentum exchange. One is a phenomenological one-parameter extension to $w$CDM, and the other is a coupled quintessence model described by a Lagrangian formalism. Using a variety of high and low redshift data sets, we perform a global fitting of cosmological parameters and compare to $\Lambda$CDM, uncoupled quintessence, and $w$CDM. We find that the models are competitive with $\Lambda$CDM, even obtaining a better fit when certain data sets are included.