https://doi.org/10.1140/epjc/s10052-024-12547-6
Regular Article - Theoretical Physics
Constraints on the speed of sound in the k-essence model of dark energy
Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, Nadia, West Bengal, India
Received:
21
November
2023
Accepted:
8
February
2024
Published online:
21
February
2024
We consider a k-essence scalar field model for the late-time cosmic acceleration in which the sound speed, parametrized as 
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 
. We put constraints on the 
parameter from these observations along with other parameters. We find lower values of which are close to zero are tightly constrained. Particularly, we find mean value of 
to be 
and 
is more than 3
away from this mean value. This means these observations favor a homogeneous dark energy component compared to the clustering one.
© The Author(s) 2024
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