相关论文: New Constraints on the Early Expansion History
We examine model independent constraints on the high redshift and prerecombination expansion history from cosmic microwave background observations, using a combination of principal component analysis and other techniques. This can be…
We constrain the evolution of the dark energy density from Cosmic Microwave Background, Large Scale Structure and Supernovae Ia measurements. While Supernovae Ia are most sensitive to the equation of state $w_0$ of dark energy today, the…
We constrain cosmological parameters using only Hubble parameter data and quantify the impact of future Hubble parameter measurements on parameter estimation for the most typical dark energy models. We first constrain cosmological…
Full suite of the present day Cosmic Microwave background (CMB) data, when combined with weak prior information on the Hubble constant and the age of the Universe, or the Large-Scale structure, provides strong indication for a non-zero…
The cosmological constant and many other possible origins for acceleration of the cosmic expansion possess variations in the dark energy properties slow on the Hubble time scale. Given that models with more rapid variation, or even phase…
The cosmic expansion history proceeds in broad terms from a radiation dominated epoch to matter domination to an accelerated, dark energy dominated epoch. We investigate whether intermittent periods of acceleration are possible in the early…
We present new determinations of the cosmic expansion history from red-envelope galaxies. We have obtained for this purpose high-quality spectra with the Keck-LRIS spectrograph of red-envelope galaxies in 24 galaxy clusters in the redshift…
We examine flat models containing a dark matter component and an arbitrary dark energy component, subject only to the constraint that the dark energy satisfies the weak energy condition. We determine the constraints that these conditions…
We present a model-independent reconstruction of the early expansion and thermal histories of the universe, obtained from light element abundance measurements. The expansion history is tightly constrained around the onset of the Big Bang…
Early dark energy models, for which the contribution to the dark energy density at high redshifts is not negligible, influence the growth of cosmic structures and could leave observable signatures that are different from the standard…
We model the expansion history of the Universe as a Gaussian Process and find constraints on the dark energy density and its low-redshift evolution using distances inferred from the Luminous Red Galaxy (LRG) and Lyman-alpha (Ly$\alpha$)…
We forecast the expected cosmological constraints from a combination of probes of both the universal expansion rate and matter perturbation growth, in the form of weak lensing tomography, galaxy tomography, supernovae, and the cosmic…
Using an approximate likelihood method adapted to band--power estimates, we analyze the ensemble of first generation cosmic microwave background anisotropy experiments to deduce constraints over a six--dimensional parameter space describing…
One of the most compelling tasks of modern cosmology is to constrain the expansion history of the Universe, since this measurement can give insights on the nature of dark energy and help to estimate cosmological parameters. In this letter…
We have assembled a compilation of observational Hubble parameter measurements estimated with the differential evolution of cosmic chronometers, in the redshift range 0<z<1.75. This sample has been used, in combination with CMB data and…
We discuss the cosmological degeneracy between the Hubble parameter H(z), the age of the universe and cosmological parameters describing simple variations from the minimal LCDM model. We show that independent determinations of the Hubble…
From a combination of probes including the cosmic microwave background (WMAP7+SPT), Hubble constant (HST), baryon acoustic oscillations (SDSS+2dFGRS), and supernova distances (Union2), we have explored the extent to which the constraints on…
Decaying Dark Energy models modify the background evolution of the most common observables, such as the Hubble function, the luminosity distance and the Cosmic Microwave Background temperature-redshift scaling relation. We use the most…
In this paper, we study the cosmological constraints from the measurements of Hubble parameters---$H(z)$ data. Here, we consider two kinds of $H(z)$ data: the direct $H_0$ probe from the Hubble Space Telescope (HST) observations of Cepheid…
We use the Constitution supernova, the baryon acoustic oscillation, the cosmic microwave background, and the Hubble parameter data to analyze the evolution property of dark energy. We obtain different results when we fit different baryon…