Dynamical Dark Energy Implies a Coupled Dark Sector: Insights from DESI DR2 via a Data-Driven Approach

Abstract

Recent observations from the Dark Energy Spectroscopic Instrument (DESI) Data Release 2 (DR2) have revealed compelling evidence for dynamical dark energy, challenging the $\Lambda$CDM paradigm. In this work, we adopt a data-driven, model-independent approach to reconstruct the dark energy equation of state (EoS) and its potential interaction with dark matter using combined background cosmological datasets, including DESI DR2, cosmic chronometers, observational Hubble data, and Type Ia supernovae. Using Gaussian Process regression and a non-parametric formalism, we first confirm a $\sim 2\sigma$ indication of dynamical dark energy, featuring a phantom crossing around redshift $z\sim 0.4$, consistent with DESI results. We then explore the implications of dynamical EoS from DESI DR2 for dark sector coupling. Incorporating priors on the EoS from DESI DR2, we find a $\sim 2\sigma$ signal for non-zero interactions between dark energy and dark matter at low redshift. Our results suggest that if DESI's evidence for time-varying dark energy is confirmed, a coupled dark sector may be a necessary extension beyond $\Lambda$CDM.

7 pages, 2 figures, published in PRD

References in corpus (61)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• Dynamics of dark energy
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• Detection of the Baryon Acoustic Peak in the Large-Scale Correlation Function of SDSS Luminous Red Galaxies
• Modified Gravity and Cosmology
• Cosmological parameters from SDSS and WMAP
• The Complete Light-curve Sample of Spectroscopically Confirmed Type Ia Supernovae from Pan-STARRS1 and Cosmological Constraints from The Combined Pantheon Sample
• Exploring the Expansion History of the Universe
• A Comprehensive Measurement of the Local Value of the Hubble Constant with 1 km/s/Mpc Uncertainty from the Hubble Space Telescope and the SH0ES Team
• Essentials of k-essence
• Coupled Quintessence
• Models of f(R) Cosmic Acceleration that Evade Solar-System Tests
• DESI 2024 VI: Cosmological Constraints from the Measurements of Baryon Acoustic Oscillations
• Baryon Acoustic Oscillations in the Lyα forest of BOSS DR11 quasars
• Quintessence: A Review
• Dark Matter and Dark Energy Interactions: Theoretical Challenges, Cosmological Implications and Observational Signatures
• Quasar-Lyman $\alpha$ Forest Cross-Correlation from BOSS DR11 : Baryon Acoustic Oscillations
• Reconstruction of dark energy and expansion dynamics using Gaussian processes
• Non-minimal dark sector physics and cosmological tensions
• Can interacting dark energy solve the $H_0$ tension?
• Measurement of BAO correlations at $z=2.3$ with SDSS DR12 \lya-Forests
• Deep Learning for Real-time Gravitational Wave Detection and Parameter Estimation: Results with Advanced LIGO Data
• KiDS+VIKING-450: Cosmic shear tomography with optical+infrared data
• Interacting dark energy in the early 2020s: a promising solution to the $H_0$ and cosmic shear tensions
• Tale of stable interacting dark energy, observational signatures, and the $H_0$ tension
• Cosmology with Interaction between Phantom Dark Energy and Dark Matter and the Coincidence Problem
• Dynamics of dark energy with a coupling to dark matter
• Super-acceleration as Signature of Dark Sector Interaction
• Gaussian Process Cosmography
• Tracking and coupled dark energy as seen by WMAP
• Type Ia Supernova Distances at z > 1.5 from the Hubble Space Telescope Multi-Cycle Treasury Programs: The Early Expansion Rate
• $H_0$ from cosmic chronometers and Type Ia supernovae, with Gaussian Processes and the novel Weighted Polynomial Regression method
• Baryon acoustic oscillations from the cross-correlation of Ly$\alpha$ absorption and quasars in eBOSS DR14
• Baryon acoustic oscillations at z = 2.34 from the correlations of Ly$\alpha$ absorption in eBOSS DR14
• Quintessence and phantom cosmology with non-minimal derivative coupling
• Dark Energy versus Modified Gravity
• The Dynamics of Quintessence, The Quintessence of Dynamics
• The BAHAMAS project: the CMB--large-scale structure tension and the roles of massive neutrinos and galaxy formation
• The Cardassian expansion revisited: constraints from updated Hubble parameter measurements and Type Ia Supernovae data
• Robust Preference for Dynamical Dark Energy in DESI BAO and SN Measurements
• Interacting Dark Energy after DESI Baryon Acoustic Oscillation measurements
• Assessing observational constraints on dark energy
• KiDS+VIKING-450 and DES-Y1 combined: Mitigating baryon feedback uncertainty with COSEBIs
• Model-independent reconstruction of $f(T)$ gravity from Gaussian Processes
• Constraints on Interacting Dark Energy Models from the DESI Baryon Acoustic Oscillation and DES Supernovae Data
• Reconstructing the interaction between dark energy and dark matter using Gaussian Processes
• Quintessential interpretation of the evolving dark energy in light of DESI
• Interpreting DESI 2024 BAO: late-time dynamical dark energy or a local effect?
• Quantifying the $S_8$ tension with the Redshift Space Distortion data set
• Cosmological constraints from noisy convergence maps through deep learning
• Quantifying the $S_8$ tension and evidence for interacting dark energy from redshift-space distortion measurements
• Gaussian processes reconstruction of modified gravitational wave propagation
• Late-Time constraints on Interacting Dark Energy: Analysis independent of $H_0$, $r_d$ and $M_B$
• Quantifying the evidence for the current speed-up of the Universe with low and intermediate-redshift data. A more model-independent approach
• Sign Switching in Dark Sector Coupling Interactions as a Candidate for Resolving Cosmological Tensions
• A data-driven Reconstruction of Horndeski gravity via the Gaussian processes
• A Fully Self-Consistent Cosmological Simulation Pipeline for Interacting Dark Energy Models
• Dark Matter Halos in Interacting Dark Energy Models: Formation History, Density Profile, Spin and Shape
• Constraining interacting dark energy models with the halo concentration-mass relation
• Model-Independent Perspectives on Coupled Dark Energy and the Swampland

Cited by in corpus (15)

• Quintessence and phantoms in light of DESI 2025
• Exploring non-cold dark matter in a scenario of dynamical dark energy with DESI DR2 data
• Robust evidence for dynamical dark energy in light of DESI DR2 and joint ACT, SPT, and Planck data
• Barrow and Tsallis entropies after the DESI DR2 BAO data
• Model-independent cosmological inference after the DESI DR2 data with improved inverse distance ladder
• Interacting dark energy after DESI DR2: a challenge for $\Lambda$CDM paradigm?
• DESIgning concordant distances in the age of precision cosmology: the impact of density fluctuations
• Testing the cosmic distance duality relation with baryon acoustic oscillations and supernovae data
• Revisiting the phenomenologically emergent dark energy model: is non-zero equation of state of dark matter favored by DESI DR2?
• Measuring neutrino mass in light of ACT DR6 and DESI DR2
• Modified cosmology through generalized mass-to-horizon entropy: observational constraints from DESI DR2 BAO data
• Constraints on Generalized Gravity-Thermodynamic Cosmology from DESI DR2
• Observational constraints on the modified cosmology inspired by string T-duality
• Unifying the Dark Sector with the New Generalized Chaplygin Gas: Observational Constraints
• Constraining Spatial Curvature with Priors from Swampland Conjectures