Constraint on Momentum-coupled Dark Energy using DESI DR2

TL;DR

This paper investigates momentum-coupled dark energy models with axion and inverse power law potentials, constraining them with recent observational data, and finds they are competitive with or preferred over the standard cosmological model, with a negative coupling parameter.

Contribution

It introduces and constrains two scalar field dark energy models with momentum exchange, analyzing their stability and observational viability using MCMC methods.

Findings

Both models show a preference over $\\Lambda$CDM, especially with Supernova data.

The coupling parameter is negative with no lower bound, indicating possible momentum exchange.

Late-time attractors are dark energy dominated, with early stiff fluid behavior.

Abstract

In this work, we study two scalar field driven dark energy models characterized by the axion potential and the inverse power law potential, each coupled to dark matter through a momentum exchange interaction. By formulating the dynamics as an autonomous system, we identify the equilibrium points and analyze their stability. To constrain these models, we utilize observational data from Pantheon Plus Type Ia Supernovae, DES Y5, DESI DR2 BAO, and Planck 2018 CMB compressed likelihood, employing Markov Chain Monte Carlo (MCMC) methods. Both potentials exhibit weak to strong preference over the $\Lambda$CDM model, with a particularly strong preference for the momentum-coupled scenario when Supernova data are included in the analysis. Furthermore, we find the coupling parameter to be negative, with no lower bound, for both potentials. This suggests that momentum-exchange coupling between the dark sectors cannot be ruled out. From the stability analysis, we observe that for both potentials, the late-time attractor corresponds to a dark energy dominated phase, and the scalar field can behave as a stiff fluid during the early epoch.