Bayesian reconstruction and exhaustive symbolic regression on CMB, BAO, and supernova data yield the one-parameter dark energy parametrization w(a) = w0 / sqrt(a) that fits observations comparably to CPL and better than LambdaCDM.
hub Canonical reference
Cosmological constraints on curved quintessence
Canonical reference. 91% of citing Pith papers cite this work as background.
abstract
Dynamical dark energy has gained renewed interest due to recent theoretical and observational developments. In the present paper, we focus on a string-motivated dark energy set-up, and perform a detailed cosmological analysis of exponential quintessence with potential $V=V_0 e^{-\lambda\phi}$, allowing for non-zero spatial curvature. We first gain some physical intuition into the full evolution of such a scenario by analysing the corresponding dynamical system. Then, we test the model using a combination of Planck CMB data, DESI BAO data, as well as recent supernovae datasets. For the model parameter $\lambda$, we obtain a preference for nonzero values: $\lambda = 0.48^{+0.28}_{-0.21},\; 0.68^{+0.31}_{-0.20},\; 0.77^{+0.18}_{-0.15}$ at 68% C.L. when combining CMB+DESI with Pantheon+, Union3 and DES-Y5 supernovae datasets respectively. We find no significant hint for spatial curvature. We discuss the implications of current cosmological results for the exponential quintessence model, and more generally for dark energy in string theory.
hub tools
citation-role summary
citation-polarity summary
roles
background 11representative citing papers
Bin-wise uncorrelated reconstruction from DESI/SDSS BAO and Pantheon+/Union3.1/DES-Dovekie supernovae yields dark energy density peaking then declining and equation of state oscillating with phantom crossing near z~0.7, consistent across datasets at moderate significance.
A sign-switching dark energy model (Λ_s CDM) recovers positive effective neutrino masses (0.055 ± 0.050 eV) consistent with oscillation data, unlike ΛCDM which prefers negative values (-0.075 eV), for DESI DR2 + CMB + supernova fits with z_† > 2.4.
A non-canonical generalized Brans-Dicke theory admits background cosmological solutions matching Lambda CDM characteristics for constant, power-law, and exponential potentials, with dynamics distinct from other scalar-tensor models.
For an exponential quintessence potential, an analytic formula links the current equation-of-state w_φ0 to the potential slope λ while enforcing prior radiation and matter domination, yielding the bound λ < 1.94 at Ω_φ0 = 0.685.
Planck PR4 CMB data mildly favors dynamical dark energy, but this preference weakens when accounting for possible excess smoothing, indicating the signal may partly arise from data processing issues.
Exponential quintessence with an assumed kination epoch relaxes the dark energy fine-tuning problem by dozens of orders of magnitude relative to a cosmological constant.
Cosmological data can constrain only a handful of EFT parameters for single-scalar dark energy; extended models show modest preference over Λ but remain underdetermined and challenged by fifth forces and screening.
A swampland-inspired DM-EDE coupling is tested against DESI DR2 BAO data, showing the EDE potential construction affects late-time dark energy constraints.
Exponential IR f(T) gravity Model I alleviates Hubble tension but is disfavoured by combined Planck/ACT/SPT+DESI+Pantheon+ data; Model II is ruled out because background constraints force unphysical shifts in CMB parameters.
Upper bounds on total neutrino mass in four phenomenological interacting dark energy models are derived from DESI DR2 BAO plus CMB and SNIa data, showing strong dependence on the interaction term form and statistical preference for models that tighten the bound below the oscillation lower limit.
Two three-parameter extensions of the mAH dark energy parametrization are compared to LambdaCDM, wCDM, CPL and others using CMB, DESI BAO, H(z), RSD and three SNIa samples, yielding Delta chi-squared improvements of 6-38 and 2-5 sigma tensions with LambdaCDM.
Effective phantom dark energy is a background-level reconstruction that does not imply fundamental pathologies such as ghost instabilities or null energy condition violation by the underlying stress tensor.
Quintessence models with standard potentials give only modest improvements over Lambda to DESI data on evolving dark energy, while non-minimal couplings allow temporary phantom behavior but face tight gravity constraints except for carefully selected narrow ranges.
This review traces the history of dynamical dark energy, presents the no-go theorem against single-field crossing of w = -1, and surveys viable Quintom constructions including multi-field models and modified gravity in light of DESI DR2 hints.
A review arguing that current DESI/DES data favor Quintom-B dark energy, where the equation of state crosses w=-1 from below to above, with applications to bounces and CMB birefringence.
citing papers explorer
-
Data-Driven Discovery of a Simple Phantom-Crossing Dark Energy Parametrization
Bayesian reconstruction and exhaustive symbolic regression on CMB, BAO, and supernova data yield the one-parameter dark energy parametrization w(a) = w0 / sqrt(a) that fits observations comparably to CPL and better than LambdaCDM.
-
Reconstructing dark energy with fewer assumptions
Bin-wise uncorrelated reconstruction from DESI/SDSS BAO and Pantheon+/Union3.1/DES-Dovekie supernovae yields dark energy density peaking then declining and equation of state oscillating with phantom crossing near z~0.7, consistent across datasets at moderate significance.
-
Negative neutrino mass or negative dark energy?
A sign-switching dark energy model (Λ_s CDM) recovers positive effective neutrino masses (0.055 ± 0.050 eV) consistent with oscillation data, unlike ΛCDM which prefers negative values (-0.075 eV), for DESI DR2 + CMB + supernova fits with z_† > 2.4.
-
Cosmological Dynamics of a Non-Canonical Generalised Brans-Dicke Theory
A non-canonical generalized Brans-Dicke theory admits background cosmological solutions matching Lambda CDM characteristics for constant, power-law, and exponential potentials, with dynamics distinct from other scalar-tensor models.
-
Exponential Quintessence: Analytic Relationship Between the Current Equation of State Parameter and the Potential Parameter
For an exponential quintessence potential, an analytic formula links the current equation-of-state w_φ0 to the potential slope λ while enforcing prior radiation and matter domination, yielding the bound λ < 1.94 at Ω_φ0 = 0.685.
-
Is the $w_0w_a$CDM cosmological parameterization evidence for dark energy dynamics partially caused by the excess smoothing of Planck PR4 CMB anisotropy data?
Planck PR4 CMB data mildly favors dynamical dark energy, but this preference weakens when accounting for possible excess smoothing, indicating the signal may partly arise from data processing issues.
-
Exponential Quintessence Model: Analytical Quantification of the Fine-Tuning Problem in Dark Energy
Exponential quintessence with an assumed kination epoch relaxes the dark energy fine-tuning problem by dozens of orders of magnitude relative to a cosmological constant.
-
The Status of Single Scalar Field Dark Energy
Cosmological data can constrain only a handful of EFT parameters for single-scalar dark energy; extended models show modest preference over Λ but remain underdetermined and challenged by fifth forces and screening.
-
Imprint of swampland-inspired coupled early dark energy
A swampland-inspired DM-EDE coupling is tested against DESI DR2 BAO data, showing the EDE potential construction affects late-time dark energy constraints.
-
Cosmological Viability of Exponential Infrared $f(T)$ Gravity
Exponential IR f(T) gravity Model I alleviates Hubble tension but is disfavoured by combined Planck/ACT/SPT+DESI+Pantheon+ data; Model II is ruled out because background constraints force unphysical shifts in CMB parameters.
-
Neutrino mass constraints in interacting dark energy models after DESI DR2
Upper bounds on total neutrino mass in four phenomenological interacting dark energy models are derived from DESI DR2 BAO plus CMB and SNIa data, showing strong dependence on the interaction term form and statistical preference for models that tighten the bound below the oscillation lower limit.
-
Beyond CPL: Evidence for dynamical dark energy in three-parameter models
Two three-parameter extensions of the mAH dark energy parametrization are compared to LambdaCDM, wCDM, CPL and others using CMB, DESI BAO, H(z), RSD and three SNIa samples, yielding Delta chi-squared improvements of 6-38 and 2-5 sigma tensions with LambdaCDM.
-
Effective Phantom Dark Energy: What Cosmological Reconstruction Does and Does Not Imply
Effective phantom dark energy is a background-level reconstruction that does not imply fundamental pathologies such as ghost instabilities or null energy condition violation by the underlying stress tensor.
-
Comparing Minimal and Non-Minimal Quintessence Models to 2025 DESI Data
Quintessence models with standard potentials give only modest improvements over Lambda to DESI data on evolving dark energy, while non-minimal couplings allow temporary phantom behavior but face tight gravity constraints except for carefully selected narrow ranges.
-
The Quintom theory of dark energy after DESI DR2
This review traces the history of dynamical dark energy, presents the no-go theorem against single-field crossing of w = -1, and surveys viable Quintom constructions including multi-field models and modified gravity in light of DESI DR2 hints.
-
A short review on Quintom dark energy theory
A review arguing that current DESI/DES data favor Quintom-B dark energy, where the equation of state crosses w=-1 from below to above, with applications to bounces and CMB birefringence.
- Intertwined Constraints in Extended Cosmologies: Dark Energy, Curvature, Neutrinos, and Inflation
- DESI Dark Secrets