Phase-resolved field-space distance bounds for non-inflationary smoothing yield a master lower bound on ε_ek and imply ultra-fast-roll ekpyrosis or modified bounces to match observed red-tilted perturbations.
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Dynamics of dark energy
17 Pith papers cite this work. Polarity classification is still indexing.
17
Pith papers citing it
abstract
In this paper we review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating Universe. In particular we discuss the arguments for and recent progress made towards understanding the nature of dark energy. We review the observational evidence for the current accelerated expansion of the universe and present a number of dark energy models in addition to the conventional cosmological constant, paying particular attention to scalar field models such as quintessence, K-essence, tachyon, phantom and dilatonic models. The importance of cosmological scaling solutions is emphasized when studying the dynamical system of scalar fields including coupled dark energy. We study the evolution of cosmological perturbations allowing us to confront them with the observation of the Cosmic Microwave Background and Large Scale Structure and demonstrate how it is possible in principle to reconstruct the equation of state of dark energy by also using Supernovae Ia observational data. We also discuss in detail the nature of tracking solutions in cosmology, particle physics and braneworld models of dark energy, the nature of possible future singularities, the effect of higher order curvature terms to avoid a Big Rip singularity, and approaches to modifying gravity which leads to a late-time accelerated expansion without recourse to a new form of dark energy.
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A master screening equation is derived for luminal Horndeski gravity that recovers Vainshtein and Chameleon mechanisms and introduces Phaedrus screening with screening radius scaling linearly with source mass.
Solar tachocline production of symmetrons yields a keV-scale flux at Earth whose absorption in xenon detectors provides new complementary bounds on symmetron parameter space.
A new quintessence model with non-minimal coupling produces an effective sign-switching interaction that fits current data better than LambdaCDM or w0waCDM and accounts for late-time dark energy weakening without phantom crossing.
Ghostly quantum systems can have discrete non-dense energy spectra under classical stability conditions, providing counterexamples to spectral denseness.
An analytic bound on axion parameters in thawing quintessence is derived independently of initial conditions and used with cosmological observations plus quantum gravity constraints to exclude large regions of axion dark energy parameter space.
LTIT is a constrained interacting dark energy framework with late-activating variable coupling to CDM that keeps pre-recombination effects below 0.4 percent while permitting sub-percent to several-percent late-time shifts in growth.
Model-independent reconstruction finds 96.7-98.5% probability of phantom crossing if recombination is standard, but early new physics to ease Hubble tension weakens this preference while requiring unrealistically high matter density.
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.
Accelerating scaling attractors where DM and barotropic fluid coexist at late times arise only for DM-density-controlled interactions with energy transfer from DM.
A barotropic fluid with ω_s ≈ 0.29 and Ω_s ≈ 1.5×10^{-5} raises the inferred H0 to match SH0ES while remaining consistent with Planck CMB, DESI BAO, and Pantheon data.
Node-based reconstruction of cosmic expansion prefers stronger deceleration at z≈1.7 than smooth DE EoS parametrizations, isolating z~1.5-2 as a window where the latter may compress localized kinematic features permitted by current data.
Early dark energy resolves CMB-BAO tension and, combined with thawing quintessence, reduces overall cosmological tensions without phantom crossing.
Extended analysis of DESI DR2 data confirms robust evidence for dynamical dark energy with phantom crossing preference, stable under parametric and non-parametric modeling.
Coupled quintessence-dark matter models can produce an apparent phantom-crossing effective equation of state matching DESI preferences if the scalar field begins frozen in the radiation era.
MCMC constraints on two Lambda(t) models with DESI DR2, CC, and Pantheon+ data yield H0 ~72.5-73 km/s/Mpc, Omega_m0 near standard values in joint fits, and n~0.3 indicating mild deviation from LambdaCDM.
citing papers explorer
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Phase-resolved field-space distance bounds in ekpyrotic, bouncing and cyclic cosmologies
Phase-resolved field-space distance bounds for non-inflationary smoothing yield a master lower bound on ε_ek and imply ultra-fast-roll ekpyrosis or modified bounces to match observed red-tilted perturbations.
-
A Master Equation for Screening in Luminal Horndeski Gravity
A master screening equation is derived for luminal Horndeski gravity that recovers Vainshtein and Chameleon mechanisms and introduces Phaedrus screening with screening radius scaling linearly with source mass.
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Probing Solar Symmetrons with Direct Detection
Solar tachocline production of symmetrons yields a keV-scale flux at Earth whose absorption in xenon detectors provides new complementary bounds on symmetron parameter space.
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Non-minimally coupled quintessence with sign-switching interaction
A new quintessence model with non-minimal coupling produces an effective sign-switching interaction that fits current data better than LambdaCDM or w0waCDM and accounts for late-time dark energy weakening without phantom crossing.
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Quantum mechanics with a ghost: Counterexamples to spectral denseness
Ghostly quantum systems can have discrete non-dense energy spectra under classical stability conditions, providing counterexamples to spectral denseness.
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Bounding axion dark energy
An analytic bound on axion parameters in thawing quintessence is derived independently of initial conditions and used with cosmological observations plus quantum gravity constraints to exclude large regions of axion dark energy parameter space.
-
Late-Transition Interacting Thawer Dark Energy: Physics and Validation
LTIT is a constrained interacting dark energy framework with late-activating variable coupling to CDM that keeps pre-recombination effects below 0.4 percent while permitting sub-percent to several-percent late-time shifts in growth.
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Exploring the interplay of late-time dynamical dark energy and new physics before recombination
Model-independent reconstruction finds 96.7-98.5% probability of phantom crossing if recombination is standard, but early new physics to ease Hubble tension weakens this preference while requiring unrealistically high matter density.
-
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.
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Accelerating scaling solutions from dark matter particle creation
Accelerating scaling attractors where DM and barotropic fluid coexist at late times arise only for DM-density-controlled interactions with energy transfer from DM.
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A barotropic alternative to Early Dark Energy for alleviating the $H_0$ tension
A barotropic fluid with ω_s ≈ 0.29 and Ω_s ≈ 1.5×10^{-5} raises the inferred H0 to match SH0ES while remaining consistent with Planck CMB, DESI BAO, and Pantheon data.
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Do equation of state parametrizations of dark energy faithfully capture the dynamics of the late universe?
Node-based reconstruction of cosmic expansion prefers stronger deceleration at z≈1.7 than smooth DE EoS parametrizations, isolating z~1.5-2 as a window where the latter may compress localized kinematic features permitted by current data.
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Disentangling cosmic distance tensions with early and late dark energy
Early dark energy resolves CMB-BAO tension and, combined with thawing quintessence, reduces overall cosmological tensions without phantom crossing.
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Extended Dark Energy analysis using DESI DR2 BAO measurements
Extended analysis of DESI DR2 data confirms robust evidence for dynamical dark energy with phantom crossing preference, stable under parametric and non-parametric modeling.
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Coupled Dark Energy and Dark Matter for DESI: An Effective Guide to the Phantom Divide
Coupled quintessence-dark matter models can produce an apparent phantom-crossing effective equation of state matching DESI preferences if the scalar field begins frozen in the radiation era.
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Observational tests of \texorpdfstring{$\Lambda(t)$}{Lambda(t)} cosmology in light of DESI DR2
MCMC constraints on two Lambda(t) models with DESI DR2, CC, and Pantheon+ data yield H0 ~72.5-73 km/s/Mpc, Omega_m0 near standard values in joint fits, and n~0.3 indicating mild deviation from LambdaCDM.