Constraints on the Cosmic Expansion Rate at Redshift 2.3 from the Lyman-α Forest.

We determine the product of the expansion rate and angular-diameter distance at redshift z=2.3 from the anisotropy of Lyman-α (Lyα) forest correlations measured by the Sloan Digital Sky Survey (SDSS). Our result is the most precise from large-scale structure at z>1. Using the flat Λ cold dark matter model we determine the matter density to be Ω_{m}=0.36_{-0.04}^{+0.03} from Lyα alone. This is a factor of 2 tighter than baryon acoustic oscillation results from the same data due to our use of a wide range of scales (25

Testing Low-Redshift Cosmic Acceleration with Large-Scale Structure.

We examine the cosmological implications of measurements of the void-galaxy cross-correlation at redshift z=0.57 combined with baryon acoustic oscillation (BAO) data at 0.110σ significance from these data alone, independent of the cosmic microwave background (CMB) and supernovae. Using a nucleosynthesis prior on Ω_{b}h^{2}, we measure the Hubble constant to be H_{0}=72.3±1.9 km s^{-1} Mpc^{-1} from BAO+voids at z<2, and H_{0}=69.0±1.2 km s^{-1} Mpc^{-1} when adding Lyman-α BAO at z=2.34, both independent of the CMB. Adding voids to CMB, BAO, and supernova data greatly improves measurement of the dark energy equation of state, increasing the figure of merit by >40%, but remaining consistent with flat Λ cold dark matter.

Curvaton scenario within the minimal supersymmetric standard model and predictions for non-Gaussianity.

We provide a model in which both the inflaton and the curvaton are obtained from within the minimal supersymmetric standard model, with known gauge and Yukawa interactions. Since now both the inflaton and curvaton fields are successfully embedded within the same sector, their decay products thermalize very quickly before the electroweak scale. This results in two important features of the model: first, there will be no residual isocurvature perturbations, and second, observable non-Gaussianities can be generated with the non-Gaussianity parameter f(NL)~O(5-1000) being determined solely by the combination of weak-scale physics and the standard model Yukawa interactions.