Constraints on the speed of sound in the k-essence model of dark energy

Abstract

We consider a particular k-essence scalar field model for the late-time cosmic acceleration in which the sound speed, parametrized as $c_s$ is constant. We compute the relevant background and perturbation quantities corresponding to the observables like cosmic microwave background, type Ia supernova, cosmic chronometers, baryon acoustic oscillations, and the $f{\sigma }_8$. We put constraints on the $c_s^2$ parameter from these observations along with other parameters. We find lower values of $c_s^2$ which are close to zero are tightly constrained. Particularly, we find mean value of ${\log }_{10}(c_s^2)$ to be $-0.61$ and $c_s^2\le 10^{-3}$ is more than 3$\sigma$ away from this mean value. This means these observations favor a homogeneous dark energy component compared to the clustering one.

Minor revision, some references added, matches published version

References in corpus (23)

• Dynamics of dark energy
• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: BAO and RSD measurements from anisotropic clustering analysis of the Quasar Sample in configuration space between redshift 0.8 and 2.2
• Aspects of the cosmological "coincidence problem"
• Modified gravity models of dark energy
• Theoretical Models of Dark Energy
• Thawing quintessence with a nearly flat potential
• Does Hubble Tension Signal a Breakdown in FLRW Cosmology?
• Is Local $H_0$ At Odds With Dark Energy EFT?
• Measuring the Speed of Dark: Detecting Dark Energy Perturbations
• Constraints on the Sound Speed of Dynamical Dark Energy
• A new method to build the (inverse) distance ladder
• $k$-essence $f(R)$ Gravity Inflation
• Cosmic expansion parametrization: Implication for curvature and ${\text{H}}_0$ tension
• Pantheon update on a model-independent analysis of cosmological supernova data
• Sound speed of scalar field dark energy: weak effects and large uncertainties
• A short review on clustering dark energy
• Dynamical Systems Analysis of K-essence Model
• Observed galaxy power spectrum in cubic Galileon model
• Critical collapse in K-essence models
• Testing a dissipative kinetic k-essence model
• Statistics of Thawing K-essence Dark Energy Models

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• How Holographic is the Dark Energy? A Spline Nodal reconstruction approach