Observational Constraints on Dark Energy Models with $\Lambda$ as an Equilibrium Point

Abstract

We investigate a dynamical reconstruction of the dark energy equation of state parameter by assuming that it satisfies a law of motion described by an autonomous second-order differential equation, with the limit of the cosmological constant as an equilibrium point. We determine the asymptotic solutions of this equation and use them to construct two families of parametric dark energy models, employing both linear and logarithmic parametrization with respect to the scale factor. We perform observational constraints by using the Supernova, the Cosmic Chronometers and the Baryon Acoustic Oscillations of DESI DR2. The constraint parameters are directly related with the initial value problem for the law of motion and its algebraic properties. The analysis shows that most of the models fit the observational data well with a preference to the models of the logarithmic parametrization. Furthermore, we introduce a new class of models as generalizations of the CPL model, for which the equilibrium point is a constant value rather than the cosmological constant. These models fit the data in a similar or better way to the CPL and the $\Lambda$CDM cosmological models.

20 pages, 7 Figures, references added, datasets updated to include DESI DR2, to appear in PDU

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Cited by in corpus (15)

• Cosmological constraints on nonphantom dynamical dark energy with DESI Data Release 2 Baryon Acoustic Oscillations: A 3$\sigma$+ lensing anomaly
• Reconstructing dark energy with model independent methods after DESI DR2 BAO
• Dark Energy within the Generalized Uncertainty Principle in Light of DESI DR2
• Constraints on Barrow and Tsallis Holographic Dark Energy from DESI DR2 BAO data
• Shape of Dark Energy: Constraining Its Evolution with a General Parametrization
• Decay of $f(R)$ quintessence into dark matter: mitigating the Hubble tension?
• Beyond Two Parameters: Revisiting Dark Energy with the Latest Cosmic Probes
• Late-time Background Constraints on Linear and Non-linear Interacting Dark Energy after DESI DR2
• Revisiting CPL with sign-switching density: To cross or not to cross the NECB
• Is Dark Energy Changing? Probing the Universe's Expansion with present and future astronomical probes
• Crunching, Bouncing, and Cyclical Cosmologies from Dark Sector Interactions
• Is the $\Lambda$CDM Model in Crisis?
• Resolving the Hubble Tension in the Early Dark Energy Framework with JWST and DESI Data
• Unifying the Dark Sector with the New Generalized Chaplygin Gas: Observational Constraints
• Modifying $\Lambda$CDM dynamics via out-of-equilibrium axions: reconciling SH0ES and DESI $H_0$ values