We consider a k-essence scalar field model for the late-time cosmic acceleration in which
the sound speed, parametrized as cs is constant. We compute the relevant background and …

We propose an analytical parametrization of the comoving distance and Hubble parameter
to study the cosmic expansion history beyond the vanilla Λ CDM model. The parametrization …

For the first time, we reconstruct the dark energy equation of the state parameter w from the
combination of background and perturbation observations, specifically combining the …

A bstract The string theory swampland proposes that there is no UV-completion for an
effective field theory with an exact (metastable) de Sitter vacua, thereby ruling out standard …

We study detectability of the deviation in interacting and non-interacting cubic Galileon
models from the Λ CDM model through the 21-cm power spectrum. We show that the …

We use N-body simulation to study the structure formation in the cubic Galileon gravity
model where along with the usual kinetic and potential term we also have a higher …

This study combines cosmic chronometer (CC) Hubble parameter data with growth rate (f)
observations to constrain the $\Omega_ {\rm m0} $ parameter. Utilizing a consistency …

The cubic Galileon model containing the lowest non-trivial order action of the full Galileon
action can produce the stable late-time cosmic acceleration. This model can have a …

We consider a dark energy scenario driven by a scalar field ϕ ϕ with a pseudo-Nambu–
Goldstone boson (pNGB) type potential V (ϕ)= μ^ 4\left (1+ cos (ϕ/f)\right) V (ϕ)= μ 4 1+ cos …

This study explores the impact of cosmic curvature on structure formation through general
relativistic first-order perturbation theory, focusing on scalar fluctuations and excluding …