Related papers: Probing Dark Energy with Constellation-X
Cosmography provides a direct method to map the expansion history of the Universe in a model-independent way. Recently, different kinds of observations have been used in cosmographic analyses, such as SNe Ia and gamma ray bursts…
Statistics that capture the directional dependence of the baryon distribution in the cosmic web enable unique tests of cosmology and astrophysical feedback. We use constrained oriented stacking of thermal Sunyaev-Zel'dovich (tSZ) maps to…
We study a class of early dark energy (EDE) models, in which, unlike in standard dark energy models, a substantial amount of dark energy exists in the matter-dominated era. We self-consistently include dark energy perturbations, and show…
A huge amount of good quality astrophysical data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision…
Thermal Sunyaev-Zel'dovich (tSZ) effect and X-ray emission from galaxy clusters have been extensively used to constrain cosmological parameters. These constraints are highly sensitive to the relations between cluster masses and observables…
We introduce a galaxy cluster mass observable, $\mu_\star$, based on the stellar masses of cluster members, and we present results for the Dark Energy Survey (DES) Year 1 observations. Stellar masses are computed using a Bayesian Model…
The role of X-ray observations for cosmological studies and conclusions is briefly explored. X-rays currently yield cosmologically interesting results on the abundances, evolution and gas content of clusters of galaxies, on the clustering…
We use the Chandra measurements of the X-ray gas mass fraction of 26 rich clusters released by Allen et al. to perform constraints on the holographic dark energy model. The constraints are consistent with those from other cosmological…
The characterization of dark energy is a central task of cosmology. To go beyond a cosmological constant, we need to introduce at least an equation of state and a sound speed and consider observational tests that involve perturbations. If…
We investigate the evolution of clusters of galaxies in a sample of distant clusters with redshifts between 0.3 and 1.0. We show the abilities and limitations of combined ROSAT and ASCA data to draw cosmological conclusions. For the first…
We study the kinematics of dark matter using the massive cluster of galaxies 1E0657-56. The velocity of the "bullet" subcluster has been measured by X-ray emission from the shock front, and the masses and separation of the main and…
We focus on uncertainties in supernova measurements, in particular of individual magnitudes and redshifts, to review to what extent supernovae measurements of the expansion history of the universe are likely to allow us to constrain a…
The cosmological constraining power of modern galaxy cluster catalogs can be improved by obtaining low-scatter mass proxy measurements for even a small fraction of sources. In the context of large upcoming surveys that will reveal the…
Ongoing and upcoming surveys in x-rays and SZE are expected to jointly detect many clusters due to the large overlap in sky coverage. We show that, these clusters can be used as an ensemble of rulers to estimate the angular diameter…
The Figure of Merit Science Working Group (FoMSWG) recently forecast the constraints on dark energy that will be achieved prior to the Joint Dark Energy Mission (JDEM) by ground-based experiments that exploit baryon acoustic oscillations,…
The precision of cosmological parameters derived from galaxy cluster surveys is limited by uncertainty in relating observable signals to cluster mass. We demonstrate that a small mass-calibration follow-up program can significantly reduce…
A general method of deprojecting two-dimensional images to reconstruct the three dimensional structure of the projected object --specifically X-ray, Sunyaev-Zel'dovich (SZ) and gravitational lensing maps of rich clusters of galaxies --…
We study the power of upcoming weak lensing surveys to probe dark energy. Dark energy modifies the distance-redshift relation as well as the matter power spectrum, both of which affect the weak lensing convergence power spectrum. Some…
Two methods of constraining the properties of dark energy are weak lensing tomography and cluster counting. Uncertainties in mass calibration of clusters can be reduced by using the properties of halo clustering (the clustering of…
When using distance measurements to probe spatial curvature, the geometric degeneracy between curvature and dark energy in the distance-redshift relation typically requires either making strong assumptions about the dark energy evolution or…