ﻻ يوجد ملخص باللغة العربية
We perform a detailed forecast on how well a {sc Euclid}-like survey will be able to constrain dark energy and neutrino parameters from a combination of its cosmic shear power spectrum, galaxy power spectrum, and cluster mass function measurements. We find that the combination of these three probes vastly improves the surveys potential to measure the time evolution of dark energy. In terms of a dark energy figure-of-merit defined as $(sigma(w_{mathrm p}) sigma(w_a))^{-1}$, we find a value of 690 for {sc Euclid}-like data combined with {sc Planck}-like measurements of the cosmic microwave background (CMB) anisotropies in a 10-dimensional cosmological parameter space, assuming a $Lambda$CDM fiducial cosmology. For the more commonly used 7-parameter model, we find a figure-of-merit of 1900 for the same data combination. We consider also the surveys potential to measure dark energy perturbations in models wherein the dark energy is parameterised as a fluid with a nonstandard non-adiabatic sound speed, and find that in an emph{optimistic} scenario in which $w_0$ deviates by as much as is currently observationally allowed from $-1$, models with $hat{c}_mathrm{s}^2 = 10^{-6}$ and $hat{c}_mathrm{s}^2 = 1$ can be distinguished at more than $2sigma$ significance. We emphasise that constraints on the dark energy sound speed from cluster measurements are strongly dependent on the modelling of the cluster mass function; significantly weaker sensitivities ensue if we modify our model to include fewer features of nonlinear dark energy clustering. Finally, we find that the sum of neutrino masses can be measured with a $1 sigma$ precision of 0.015~eV, (abridged)
We investigate how well future large-scale radio surveys could measure different shapes of primordial non-Gaussianity; in particular we focus on angle-dependent non-Gaussianity arising from primordial anisotropic sources, whose bispectrum has an angl
Galaxy clusters are a recent cosmological probe. The precision and accuracy of the cosmological parameters inferred from these objects are affected by the knowledge of cluster physics, entering the analysis through the mass-observable scaling relatio
Flux ratio anomalies in strong gravitationally lensed quasars constitute a unique way to probe the abundance of non-luminous dark matter haloes, and hence the nature of dark matter. In this paper we identify double imaged quasars as a statistically e
Baryon acoustic oscillations (BAO) at low redshift provide a precise and largely model-independent way to measure the Hubble constant, H0. The 6dF Galaxy Survey measurement of the BAO scale gives a value of H0 = 67 +/- 3.2 km/s/Mpc, achieving a 1-sig
We study the constraining power on primordial non-Gaussianity of future surveys of the large-scale structure of the Universe for both near-term surveys (such as the Dark Energy Survey - DES) as well as longer term projects such as Euclid and WFIRST.