Disformal couplings in a $\Lambda$CDM background cosmology

Understand

The coupled quintessence model with disformal couplings is treated here to mimic the $\Lambda$CDM background.

• Using this approach, the quintessence potential does not have to be specified.
• The model considers a generic fluid coupled to the quintessence, which is specified to be either dark matter or a relativistic fluid.
• The background consists of a cosmological constant and another uncoupled generic fluid, to cater for three studied scenarios.