Related papers: Optimal parameterizations for observational constr…
Quintessence is a canonical scalar field introduced to explain the late-time cosmic acceleration. The cosmological dynamics of quintessence is reviewed, paying particular attention to the evolution of the dark energy equation of state w.…
As an alternative to the popular parametrisations of the dark energy equation of state, we construct a quintessence model where the scalar field has a linear dependence on the number of e-folds. Constraints on more complex models are…
Almost in all interacting dark energy models present in the literature, the stability of the model becomes potentially sensitive to the dark energy equation of state parameter $w_x$, and a singularity arises at `$w_x = -1$'. Thus, it…
We look at observational constraints on the thawing class of scalar field models proposed to explain the late time acceleration of the universe. Using the recently introduced `Statefinder Hierarchy', we compare these thawing class of models…
The explanation of the accelerated expansion of the Universe poses one of the most fundamental questions in physics and cosmology today. If the acceleration is driven by some form of dark energy, one can try to constrain the parameters…
In this work, two different models, one with cosmological constant $\Lambda$, and baryonic and dark matter (with $\omega_{dm} \neq 0$), and the other with an $X$ dark energy (with $\omega_{de} \neq -1$), and baryonic and dark matter (with…
Accurate measurements of fundamental cosmological parameters, especially the Hubble constant (H_0) and present-day matter density (\Omega_{m0}), are crucial for constraining dark energy (DE) evolution. We analyze the sensitivities of…
Dark energy dynamics in the recent universe is influenced by its evolution through the long, matter dominated expansion history. A particular dynamical property, the flow variable, remains constant in several classes of scalar field models…
We propose a phenomenological unified model for dark matter and dark energy based on an equation of state parameter $w$ that scales with the $\arctan$ of the redshift. The free parameters of the model are three constants: $\Omega_{b0}$,…
We investigate the accuracy attainable by forthcoming space-based observations of the cosmic microwave background (CMB) temperature and polarization anisotropy in constraining the dark energy density parameter $\Oq$ and equation of state…
Pad$\acute{e}$ cosmography has been widely used to probe the cosmic evolution and to investigate the nature of dark energy. In this paper, we find that the Pad$\acute{e}$ approximant can describe the cosmic evolution better than the…
We combine recent measurements of Cosmic Microwave Background Anisotropies, Supernovae luminosity distances and Baryonic Acoustic Oscillations to derive constraints on the dark energy equation of state w in the redshift range 0<z<2, using a…
We present a realistic dark energy model derived from particle physics. Our model has essentially no free parameters and has an equivalent fit to the observational data (CMB, SN1a and LSS) as LCDM and a better fit than the best effective…
We adopt a model independent method to reconstruct the dark energy equation of state by analyzing 5 sets of SNe Ia data along with Baryon Acoustic Oscillation (BAO) and Observational Hubble Data (OHD). The SNe Ia data sets include the most…
We consider a model-independent approach to constrain the equivalence redshift, $z_{eq}$, at which dark energy and the total matter (cold dark matter and baryonic) equate their magnitudes. To this aim, in the context of a homogeneous and…
We propose a class of simple dark energy models which predict a late-time dark radiation component and a distinctive time-dependent equation of state $w(z)$ for redshift $z < 3$. The dark energy field can be coupled strongly enough to…
We report the constraints on the dark energy equation-of-state w(z) using the latest 'Constitution' SNe sample combined with the WMAP5 and SDSS data. Based on the localized principal component analysis and the model selection criteria, we…
We use late Universe probes - Type Ia Supernovae from the PantheonPlus compilation, Quasars, and Dark Energy Spectroscopic Instrument (DESI) Data Release 1 (DR1) BAO data - along with Cosmic Chronometers or Megamasers to constrain various…
We study how parameter error forecasts for tomographic cosmic shear observations are affected by sky coverage, density of source galaxies, inclusion of CMB experiments, simultaneou fitting of non--dark energy parameters, and the…
In the present analysis, we explore a new version of dark energy called Barrow holographic dark energy within the framework modified gravity called $f(Q,T)$ gravity by adopting the simple homogeneous, isotropic, and spatially flat…