A varying Dark Energy effective speed of sound parameter in the phantom Universe

Abstract

We analyse the phenomenological effects of a varying Dark Energy (DE) effective speed of sound parameter, $c_{\text{sd}}^2$, on the cosmological perturbations of three phantom DE models. Each of these models induce a particular abrupt future event known as Big Rip (BR), Little Rip (LR), and Little Sibling of the Big Rip (LSBR). In this class of abrupt events, all the bound structures in the Universe would be ripped apart at a finite cosmic time. We compute the evolution of the perturbations, $f{\sigma }_8$ growth rate and forecast the current matter power spectrum. We vary the $c_{\text{sd}}^2$ parameter in the interval $[0,1]$ and compute the relative deviation with respect $c_{\text{sd}}^2=1$. In addition, we analyse the effect of gravitational potential sign flip that occurs at very large scale factors as compared with the current one.

arXiv comment15 pages, 6 figures. Improved version with an extended physical discussion. Version published in EPJC

References in corpus (51)

• A Phantom Menace? Cosmological consequences of a dark energy component with super-negative equation of state
• Phantom Energy and Cosmic Doomsday
• Can the dark energy equation-of-state parameter w be less than -1?
• Properties of singularities in (phantom) dark energy universe
• Cosmology and Fundamental Physics with the Euclid Satellite
• Inhomogeneous Equation of State of the Universe: Phantom Era, Future Singularity and Crossing the Phantom Barrier
• New physics in light of the $H_0$ tension: an alternative view
• Large-scale instability in interacting dark energy and dark matter fluids
• Reconciling Planck with the local value of $H_0$ in extended parameter space
• Dark Energy Anisotropic Stress and Large Scale Structure Formation
• Probing dark energy perturbations: the dark energy equation of state and speed of sound as measured by WMAP
• Phantom cosmologies
• Constructing Phantom Cosmologies from Standard Scalar Field Universes
• The Little Rip
• K-Essential Phantom Energy: Doomsday around the corner?
• Viscous Little Rip Cosmology
• Constraints on the sum of the neutrino masses in dynamical dark energy models with $w(z)\ge -1$ are tighter than those obtained in $\Lambda$CDM
• Effective Field Theory of Dark Energy: a Review
• "Expansion" around the vacuum equation of state - sudden future singularities and asymptotic behavior
• $H_0$ Tension, Phantom Dark Energy and Cosmological Parameter Degeneracies
• Generalized phantom energy
• Dark Energy with Phantom Crossing and the $H_0$ tension
• A combined analysis of the $H_0$ late time direct measurements and the impact on the Dark Energy sector
• Measuring the Speed of Dark: Detecting Dark Energy Perturbations
• Measuring Dark Energy Clustering with CMB-Galaxy Correlations
• Axion Phantom Energy
• 2021-$H_0$ Odyssey: Closed, Phantom and Interacting Dark Energy Cosmologies
• Dark energy with non-adiabatic sound speed: initial conditions and detectability
• The little sibling of the big rip singularity
• Combined analysis of Planck and SPTPol data favors the early dark energy models
• How clustering dark energy affects matter perturbations
• Phantom-like behaviour in dilatonic brane-world scenario with induced gravity
• Can a galaxy redshift survey measure dark energy clustering?
• Emergent Dark Energy, neutrinos and cosmological tensions
• Cosmological constraints of phantom dark energy models
• Early Cosmology Constrained
• Variable sound speed in interacting dark energy models
• Hints of dark energy anisotropic stress using Machine Learning
• Cosmological perturbations in an effective and genuinely phantom dark energy Universe
• Accuracy of the growth index in the presence of dark energy perturbations
• Affine parameterization of the dark sector: costraints from WMAP5 and SDSS
• Tradeoff between Smoother and Sooner "Little Rip"
• Can dark energy viscosity be detected with the Euclid survey?
• Constraining the Nature of Dark Energy using the SKA
• Quantum behavior of the "Little Sibling" of the Big Rip induced by a three-form field
• Effective equation of state in modified gravity and observational constraints
• $K$-essence model from the mechanical approach point of view: coupled scalar field and the late cosmic acceleration
• Revealing the non-adiabatic nature of dark energy perturbations from galaxy clustering data
• Covariance of dark energy parameters and sound speed constraints from large HI surveys
• What if gravity becomes really repulsive in the future?
• Effect of dark energy sound speed and equation of state on CDM power spectrum

Cited by in corpus (1)

• Dark energy with a shift-symmetric scalar field: obstacles, loophole hunting and dead ends