Dark Energy Parametrizations and the Curvature of the Universe
نویسندگان
چکیده
We investigate observational constraints on the curvature of the universe not restricting ourselves to a cosmological constant as dark energy, in particular allowing a dark energy equation of state to evolve with time in several ways. We use type Ia supernovae (SNeIa) data from the latest gold data set which includes 182 SNeIa, along with the cosmic microwave background shift parameter and the baryon acoustic oscillation peak. We show quantitatively that the constraint on the curvature of the universe depends on dark energy model: some popular parametrizations give constraints closely around the flat universe at 5% level (2σ C.L.) whereas some parametrizations allow the universe to be as open as Ωk ∼ 0.2.
منابع مشابه
Formation of Large Structures in the Acceleration Universe with a Hybrid Expansion Law
In the current paper, we have studied the effect of dark energy on for-mation where dark energy exists in the background. For this purpose, we used both WMAP9 and Planck data to study how the radius changes with redshift in these mod-els. We used different data sets to fix the cosmological parameters to obtain a solution for a spherical region under collapse. The mechanism of structure formation f...
متن کاملEarly and Late Transient Cosmic Acceleration Due to Curvature Inspired Dark Energy
In contrast to other models, here, it is obtained that dark energy emerges from the higher-derivative gravity with a non-linear term proportional to R with R being the Ricci scalar curvature. Interestingly, it is found that the universe begins with acceleration, which continues for a short period. Later on, universe decelerates driven by radiation and subsequently by matter. Two components of d...
متن کاملAcceleration and Deceleration in Curvature Induced Phantom Model of the Late and Future Universe, Cosmic Collapse as Well as Its Quantum Escape
Here, cosmology of the late and future universe is obtained from f(R)− gravity with non-linear curvature terms R and R (R being the Ricci scalar curvature). It is different from f(R)−dark energy models [6] where non-linear curvature terms are taken as gravitational alternative of dark energy. In the present model, neither linear nor non-linear curvature terms are taken as dark energy. Rather, d...
متن کاملProbe the curvature and dark energy
Two new one-parameter tracking behavior dark energy representations ω = ω0/(1 + z) and ω = ω0e /(1 + z) are used to probe the geometry of the Universe and the property of dark energy. The combined type Ia supernova (SN Ia), Sloan Digital Sky Survey (SDSS) and Wilkinson Microwave Anisotropy Probe (WMAP) data indicate that the Universe is almost spatially flat and that dark energy contributes abo...
متن کاملModel independent analysis of dark energy: Supernova fitting result
This paper uses the supernova data to explore the property of dark energy by some model independent methods. We first Taylor expand the scale factor a(t) and the luminosity distance dL to the fifth order to find out that the deceleration parameter q0 < 0. This result just invokes the Robertson-Walker metric. So the conclusion that the universe is expanding with acceleration is more general. The...
متن کامل