Related papers: Limits on the Dark Energy Parameters from Cosmic M…
We use all available baryon acoustic oscillation distance measurements and Hubble parameter data to constrain the cosmological constant $\Lambda$, dynamical dark energy, and spatial curvature in simple cosmological models. We find that the…
We use Hubble parameter versus redshift data from Stern, et al(2010) and Gazta\~{n}aga, et al (2009) to place constraints on model parameters of constant and time-evolving dark energy cosmological models. These constraints are consistent…
We determine the range of parameter space of Interacting Quintessence Models that best fits the recent WMAP measurements of Cosmic Microwave Background temperature anisotropies. We only consider cosmological models with zero spatial…
Measurements of the current expansion rate of the Universe, $H_0$, using standard candles, disagree with those derived from observations of the Cosmic Microwave Background (CMB). This discrepancy, known as the Hubble tension, is substantial…
We calculate the angular scale of the acoustic oscillation from the BOOMERANG and WMAP data on the cosmic microwave background (CMB) to constrain the holographic dark energy model recently proposed by Li. We find that only the phantom-like…
Observations of the cosmic microwave backgroundradiation are described to remarkable accuracy by the six-parameterLambda CDM cosmology. However, the key ingredients of this model, namely dark matter, dark energy and cosmic inflation are not…
In this paper we compare data to theory. We use a compilation of the most recent cosmic microwave background (CMB) measurements to constrain Hubble's constant h, the baryon fraction Omega_b, and the cosmological constant lambda. We fit h-,…
A six parameter cosmological model, involving a vacuum energy density that is extremely tiny compared to fundamental particle physics scales, describes a large body of increasingly accurate astronomical data. In a first part of this brief…
We introduce a new parametrization for the dark energy, led by the same idea to the linear expansion of the equation of state in scale factor $a$ and in redshift $z$, which diverges neither in the past nor future and contains the same…
We present strong evidence for dynamical dark energy that challenges the standard $\Lambda$CDM model. Several dark energy scenarios are explored, including $\omega_0\omega_a$CDM, logarithmic, exponential, JBP, and BA parameterizations,…
The $\Lambda$CDM framework offers a remarkably good description of our universe with a very small number of free parameters, which can be determined with high accuracy from currently available data. However, this does not mean that the…
The cosmic expansion is computed for various dynamical vacuum models $\Lambda(H)$ and confronted to the Cosmic Microwave Background (CMB) power spectrum from Planck. We also combined CMB in a joint analysis with other probes in order to…
We examine the decay vacuum model with a parameter $\epsilon$ that indicates the vacuum energy decay rate. By constraining this model with cosmic microwave background radiation, baryon acoustic oscillation, type Ia supernovae and 30 H(z)…
In this work we study the consequences of allowing non pressureless dark matter when determining dark energy constraints. We show that present-day dark energy constraints from low-redshift probes are extremely degraded when allowing this…
We examine the cosmic microwave background (CMB) anisotropy for signatures of early quintessence dark energy -- a non-negligible quintessence energy density during the recombination and structure formation eras. In contrast to a…
Recent analysis of the combined data of cosmic microwave background, galaxy clustering and supernovae type Ia observations have set strong constraints on the equation of state parameter $w_X$. The upper bound $w_X < -0.82$ at 95% c.l. rules…
From measurements of the cosmic microwave background (CMB), the effective number of neutrino is found to be close to the standard model value Neff = 3.046 for the \LambdaCDM cosmology. One can obtain the same CMB angular power spectrum as…
In this work, we have proposed a general dark energy density parametrization to study the evolution of the universe. We have also constrained the model parameters using the combination of Type Ia supernova (SNIa), baryonic acoustic…
The conventional $\Lambda$CDM cosmological model supplemented by the inflation concept describes the Universe very well. However, there are still a few concerns: new Planck data impose constraints on the shape of the inflaton potential,…
We consider a dynamical model for dark energy based on an ultralight mass scalar field with very large-scale inhomogeneities. This model may cause observable impacts on the anisotropic properties of the cosmic microwave background (CMB)…