Related papers: Exploring Parameter Constraints on Quintessential …
We confront two types of phantom dark energy potential with observational data. The models we consider are the power-law potential, $V\propto {\phi}^{\mu}$, and the exponential potential, $V\propto \exp({\lambda}{\phi}/{M_P})$. We fit the…
We determine the best-fit values and confidence limits for dynamical dark energy parameters together with other cosmological parameters on the basis of different datasets which include WMAP9 or Planck-2013 results on CMB anisotropy, BAO…
In this paper we analyze the constraints on the property of dark energy from cosmological observations. Together with SNe Ia Gold sample, WMAP, SDSS and 2dFGRS data, we include 69 long Gamma-Ray Bursts (GRBs) data in our study and perform…
We introduce a unified model of early and late dark energy. We call it {\it quintessential early dark energy} model where early and late dark energy are explained by a single scalar field {\it i.e.}, two different energy scales are related…
The consistency of some dynamical dark energy models based on Gauss-Bonnet invariant, ${\cal G}$, is studied compared with cosmological observational tests. The investigated models are modified form of Gauss Bonnet dark energy, MGB-DE and…
In this paper, we propose a new pressure parametric model of the total cosmos energy components in a spatially flat Friedmann-Robertson-Walker (FRW) universe and then reconstruct the model into quintessence and phantom scenarios,…
We study observational constraints on cosmological models with a quintessence field in the form of a dynamical pseudo Nambu-Goldstone boson. After reviewing the properties of the solutions, from a dynamical systems phase space analysis, we…
We analyse DESI BAO, CMB, and supernova data to explore the physical origin of the DESI indication for dynamical dark energy. Beyond the standard CPL parametrization, we explore truncated alternatives and quintessence models. We conclude…
We introduce a power-law parameterized quintessence model for the dark energy which accelerate universe at the low redshifts while behaves as an ordinary matter for the early universe. We construct a unique scalar potential for this…
In this study, we modify the $\Lambda$CDM model by introducing a deformed algebra within the framework of the Generalized Uncertainty Principle (GUP). We formulate the modified Raychaudhuri equation, where new terms are introduced which…
Although well motivated from theoretical arguments, the cosmological constant \emph{barrier}, i.e., the imposition that the equation-of-state parameter of dark energy ($\omega_x \equiv p_x/\rho_x$) is $\geq -1$, seems to introduce bias in…
Thawing quintessence scalar field models with the various potential forms to explain the late-time cosmic acceleration are compared to the {\Lambda}CDM model in detail by analyzing cosmological parameters with a set of observational data…
The quintessence dark energy potential is reconstructed in a model-independent way. Reconstruction relies on a Gaussian process and on available expansion-rate data. Specifically, 40-point values of $H(z)$ are used, consisting of a 30-point…
We study the vacuum dynamics of pseudo-Nambu-Goldstone bosons (pNGBs) for $SO(N+1) \rightarrow SO(N)$ spontaneous and explicit symmetry breaking. We determine the magnitude of explicit symmetry breaking consistent with an EFT description of…
Dark Matter (DM) and Dark Energy (DE) can be both described in terms of ultra-light Pseudo-Goldstone-Bosons (PGB) with masses m_{DM} ~ 10^{-23}eV and m_{DE} <= 10^{-33}eV respectively. Following Barbieri et al, we entertain the possibility…
We examine a dark energy model where a scalar unparticle degree of freedom plays the role of quintessence. In particular, we study a model where the unparticle degree of freedom has a standard kinetic term and a simple mass potential, the…
We highlight the unexpected impact of nucleosynthesis and other early universe constraints on the detectability of tracking quintessence dynamics at late times, showing that such dynamics may well be invisible until the unveiling of the…
Combined measurements of Baryon Acoustic Oscillations (BAO) from the Dark Energy Spectroscopic Survey (DESI), the Cosmic Microwave Background (CMB) and Type Ia Supernovae (SN Ia), have recently challenged the $\Lambda$-Cold Dark Matter…
The equation of state characterizing the dark energy component is constrained by combining Chandra observations of the X-ray luminosity of galaxy clusters with independent measurements of the baryonic matter density and the latest…
The coupling between the dark components provides a new approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with…