Related papers: Surveying the dark side
The distribution of angles subtended between pairs of galaxies and the line of sight,which is uniform in real space, is distorted by their peculiar motions, and has been proposed as a probe of cosmic expansion. We test this idea using…
Observations of gamma-ray bursts up to $z\sim 9$ are best suited to study the possible evolution of the Universe equation of state at intermediate redshifts. We apply the Combo-relation to a sample of 174 gamma ray bursts to investigate…
Measurements of time delays between multiple quasar images produced by strong lensing are reaching a sensitivity that makes them a promising cosmological probe. Future surveys will provide significantly more measurements, reaching…
The observed cosmic acceleration today could be due to an unknown energy component (dark energy), or a modification to general relativity (modified gravity). If dark energy models and modified gravity models are required to predict the same…
A space-based galaxy redshift survey would have enormous power in constraining dark energy and testing general relativity, provided that its parameters are suitably optimized. We study viable space-based galaxy redshift surveys, exploring…
We optimize the design of future spectroscopic redshift surveys for constraining the dark energy via precision measurements of the baryon acoustic oscillations (BAO), with particular emphasis on the design of the Wide-Field Multi-Object…
Understanding the origin of the accelerated expansion of the Universe poses one of the greatest challenges in physics today. Lacking a compelling fundamental theory to test, observational efforts are targeted at a better characterization of…
We demonstrate that cosmic microwave background observations consistent with a cosmological constant universe predict in a well-defined sense that lower redshift measures will nearly automatically deliver w=-1 for the dark energy equation…
The use of Type Ia supernovae as calibrated standard candles is one of the most powerful tools to study the expansion history of the universe and thereby its energy components. While the analysis of some ~50 supernovae at redshifts around…
We study future constraints on dark energy parameters determined from several combinations of CMB experiments, supernova data, and weak lensing surveys with and without tomography. In this analysis, we look in particular for combinations…
We investigate how precisely we can determine the nature of dark energy such as the equation of state (EoS) and its time dependence by using future observations of 21 cm fluctuations at the epoch of reionization (6.8 <~ z <~ 10) such as…
The next generation of weak gravitational lensing surveys is capable of generating good measurements of cosmological parameters, provided that, amongst other requirements, adequate redshift information is available for the background…
We review the implications of having a non-trivial matter component in the universe and the potential for detecting such a component through the matter power spectrum and ISW effect. We adopt a phenomenological approach and consider the…
One of the main challenges of modern cosmology is to investigate the nature of dark energy in our Universe. The properties of such a component are normally summarised as a perfect fluid with a (potentially) time-dependent equation-of-state…
Mapping the expansion of the universe gives clues to the underlying physics causing the recently discovered acceleration of the expansion, and enables discrimination among cosmological models. We examine the utility of measuring the rate of…
The dark energy component of the universe is often interpreted either in terms of a cosmological constant or as a scalar field. A generic feature of the scalar field models is that the equation of state parameter w= P/rho for the dark…
We present forecasts on the capability of future wide-area high-sensitivity X-ray surveys of galaxy clusters to yield constraints on the parameters defining the Dark Energy (DE) equation of state (EoS). Our analysis is carried out for…
We suggest to use the observationally measured and theoretically justified correlation between size and rotational velocity of galactic discs as a viable method to select a set of high redshift standard rods which may be used to explore the…
We investigate theoretical and observational aspects of a time-dependent parameterization for the dark energy equation of state (EoS) $w(z)$, which is a well behaved function of the redshift $z$ over the entire cosmological evolution, i.e.,…
An interesting probe of the nature of dark energy is the measure of its sound speed, $c_s$. We review the significance for constraining sound speed models of dark energy using large neutral hydrogen (HI) surveys with the Square Kilometre…