Cosmological parameters from combining the Lyman-α forest with CMB, galaxy clustering and SN constraints

By Uros Seljak, A. Slosar, P. Mcdonald. 2006

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We combine the Ly-α forest power spectrum (LYA) from the Sloan Digital Sky Survey (SDSS) and high resolution spectra with cosmic microwave background (CMB) including three-year WMAP, and supernovae (SN) and galaxy clustering constraints to derive new constraints on cosmological parameters. The existing LYA power spectrum analysis is supplemented by constraints on the mean flux decrement derived using a principle component analysis for quasar continua, which improves the LYA constraints on the linear power. We find some tension between the WMAP3 and LYA power spectrum amplitudes, at the ∼2σ level, which is partially alleviated by the inclusion of other observations: we find σ8 = 0.85 ± 0.02 compared to σ8 = 0.80 ± 0.03 without LYA. For the slope, we find ns = 0.965 ± 0.012. We find no evidence for the running of the spectral index in the combined analysis, dn/dlnk = −(1.5 ± 1.2) × 10−2, in agreement with inflation. The limits on the sum of neutrino masses are significantly improved: at 95% (<0.32 eV at 99.9%). This result, when combined with atmospheric and solar neutrino mixing constraints, requires that the neutrino masses cannot be degenerate, m3/m1>1.3 (95% c.l.). Assuming a thermalized fourth neutrino, we find ms<0.26 eV at 95% c.l. and such a neutrino cannot be an explanation for the LSND results. In the limits of massless neutrinos, we obtain the effective number of neutrinos Nνeff = 5.3−0.6+0.4−1.7+2.1−2.5+3.8 and Nνeff = 3.04 is allowed only at 2.4 sigma. The constraint on the dark energy equation of state is w = −1.04 ± 0.06. The constraint on curvature is Ωk = −0.003 ± 0.006. Cosmic strings limits are Gμ<2.3 × 10−7 at 95% c.l. and correlated isocurvature models are also tightly constrained.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/ff2561b1455195f460df1c24acf030dcd9bbdcb1

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Citations in the corpus

The physics of the intergalactic medium (2007, methodology): “Combining the Lyα flux power spectrum measurements from the SDSS (McDonald et al., 2006, 2005b) with CMB, supernovae and galaxy clustering constraints, Seljak et al. (2006) find the Lyα flux power spectrum increases σ8 = 0.80±0.03 to σ8 = 0.85±0.02.”
Massive neutrinos and the non‐linear matter power spectrum (2011, background): “0.6 eV (Elgaroy et al. 2002; Seljak et al. 2006; Tegmark et al. 2006; Gratton et al. 2008; Mantz et al. 2010; Thomas et al. 2010; Reid et al. 2010).”
Gravitational probes of dark matter physics (2017, background): “he time of structure formation [117, 118], at most has self-interactions below the scale of the strong nuclear force [119], and forms gravitationally bound structures down to a mass of at least 108 M [120, 121, 122, 123]. If dark matter were a purely non-collisional, non-interacting, non-relativisti”
CHANDRA CLUSTER COSMOLOGY PROJECT III: COSMOLOGICAL PARAMETER CONSTRAINTS (2008, methodology): “Our constraints on neutrino mass are still weaker than the published results from Ly-α forest data, ∑mν < 0.17 eV (Seljak et al. 2006).”
A LARGER ESTIMATE OF THE ENTROPY OF THE UNIVERSE (2009, methodology): “The radius of the observable universe (or particle horizon) is Here a ( t ) is the time-dependent scalefactor of the universe given by the Friedmann equation for a ﬂat cosmology Hubble’s constant and the matter density parameter are taken from Seljak et al. (2006): h = H / 100 km s - 1 Mpc - 1 = 0 .”
The black hole and cosmological solutions in IR modified Hořava gravity (2009, unknown): “026 [36] in the current epoch (a = 1) for the deviation from the critical density, Ωk = μ (2)k|ΛW |L(2)P/2a(2)H(2)R(2) 0M(2) P, Hubble parameter H ≡ ȧ/a, the ratio of Planck mass and length MP/LP ≡ 2(3λ − 1)/κ(2), k = −1, I get μ ∼ 0.”
History of dark matter (2018, unknown): “VII), the combination of constraints from x-ray observations and measurements of the Lyman-α forest (Viel et al., 2005; Seljak, Slosar, and McDonald, 2006) disfavor sterile neutrino dark matter over this entire mass range.”
Constraint on neutrino masses from SDSS-III/BOSS Lyα forest and other cosmological probes (2014, background): “with increasing precision over the years, and a comparison of these predictions with observational data has led to several Lyα constraints on neutrino masses [14, 22–24].”
Simulations and Analytic Calculations of Bubble Growth during Hydrogen Reionization (2006, methodology): “When combined with other datasets, such as the Lyman-α forest (Lewis 2006; Seljak et al. 2006), and weak lensing (see e.g. section 4.1.7 and Table 6 of Spergel et al. 2006), a higher value of σ8 can be found.”