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Register a new userMeasurements of the cosmological parameters $Omega_m$, $Omega_k$, $Omega_textrm{de}(a)$, $H_0$, and $sum m_ u$
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B. Hoeneisen
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From Baryon Acoustic Oscillation measurements with Sloan Digital Sky Survey SDSS DR14 galaxies, and the acoustic horizon angle $theta_*$ measured by the Planck Collaboration, we obtain $Omega_m = 0.2724 pm 0.0047$, and $h + 0.020 cdot sum{m_ u} = 0.7038 pm 0.0060$, assuming flat space and a cosmological constant. We combine this result with the 2018 Planck `TT,TE,EE$+$lowE$+$lensing analysis, and update a study of $sum m_ u$ with new direct measurements of $sigma_8$, and obtain $sum m_ u = 0.27 pm 0.08$ eV assuming three nearly degenerate neutrino eigenstates. Measurements are consistent with $Omega_k = 0$, and $Omega_textrm{de}(a) = Omega_Lambda$ constant.
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We measure the baryon acoustic oscillation (BAO) observables $hat{d}_alpha(z, z_c)$, $hat{d}_z(z, z_c)$, and $hat{d}_/(z, z_c)$ as a function of redshift $z$ in the range 0.1 to 0.7 with Sloan Digital Sky Survey (SDSS) data release DR13. These observables are independent and satisfy a consistency relation that provides discrimination against miss-fits due to background fluctuations. From these measurements and the correlation angle $theta_textrm{MC}$ of fluctuations of the Cosmic Microwave Background (CMB) we obtain $Omega_k = -0.015 pm 0.030$, $Omega_{textrm{DE}} + 2.2 Omega_k = 0.717 pm 0.004$ and $w_1 = 0.37 pm 0.61$ for dark energy density allowed to vary as $Omega_{textrm{DE}}(a) = Omega_{textrm{DE}} [ 1 + w_1 ( 1 - a)]$. We present measurements of $Omega_{textrm{DE}}(a)$ at six values of the expansion parameter $a$. Fits with several scenarios and data sets are presented. The data is consistent with space curvature parameter $Omega_k = 0$ and $Omega_{textrm{DE}}(a)$ constant.
We define Baryon Acoustic Oscillation (BAO) observables $hat{d}_alpha(z, z_c)$, $hat{d}_z(z, z_c)$, and $hat{d}_/(z, z_c)$ that do not depend on any cosmological parameter. From each of these observables we recover the BAO correlation length $d_textrm{BAO}$ with its respective dependence on cosmological parameters. These BAO observables are measured as a function of redshift $z$ with the Sloan Digital Sky Survey (SDSS) data release DR12. From the BAO measurements alone, or together with the correlation angle $theta_textrm{MC}$ of the Cosmic Microwave Background (CMB), we constrain the curvature parameter $Omega_k$ and the dark energy density $Omega_textrm{DE}(a)$ as a function of the expansion parameter $a$ in several scenarios. These observables are further constrained with external measurements of $h$ and $Omega_textrm{b} h^2$. We find some tension between the data and a cosmology with flat space and constant dark energy density $Omega_textrm{DE}(a)$.
We define Baryon Acoustic Oscillation (BAO) distances $hat{d}_alpha(z, z_c)$, $hat{d}_z(z, z_c)$, and $hat{d}_/(z, z_c)$ that do not depend on cosmological parameters. These BAO distances are measured as a function of redshift $z$ with the Sloan Digital Sky Survey (SDSS) data release DR12. From these BAO distances alone, or together with the correlation angle $theta_textrm{MC}$ of the Cosmic Microwave Background (CMB), we constrain the cosmological parameters in several scenarios. We find $4.3 sigma$ tension between the BAO plus $theta_textrm{MC}$ data and a cosmology with flat space and constant dark energy density $Omega_textrm{DE}(a)$. Releasing one and/or the other of these constraints obtains agreement with the data. We measure $Omega_textrm{DE}(a)$ as a function of $a$.
The clustering amplitude of 7143 clusters from the Sloan Digital Sky Survey (SDSS) is found to increase with cluster mass, closely agreeing with the Gaussian random field hypothesis for structure formation. The amplitude of the observed cluster correlation exceeds the predictions from pure cold dark matter (CDM) simulation by $simeq 6%$ for the standard Planck-based values of the cosmological parameters. We show that this excess can be naturally accounted for by free streaming of light neutrinos, which opposes gravitational growth, so clusters formed at fixed mass are fewer and hence more biased than for a pure CDM density field. An enhancement of the cluster bias by 7% matches the observations, corresponding to a total neutrino mass, $m_{ u} = 0.119 pm 0.034$ eV at 67% confidence level, for the standard relic neutrino density. If ongoing laboratory experiments favor a normal neutrino mass hierarchy then we may infer a somewhat larger total mass than the minimum oscillation based value, $sum m_{ u} simeq 0.056eV$, with 90% confidence. Much higher precision can be achieved by applying our method to a larger sample of more distant clusters with weak lensing derived masses.
We present cosmological constraints from the combination of the full mission 9-year WMAP release and small-scale temperature data from the pre-Planck ACT and SPT generation of instruments. This is an update of the analysis presented in Calabrese et al. 2013 and highlights the impact on $Lambda$CDM cosmology of a 0.06 eV massive neutrino - which was assumed in the Planck analysis but not in the ACT/SPT analyses - and a Planck-cleaned measurement of the optical depth to reionization. We show that cosmological constraints are now strong enough that small differences in assumptions about reionization and neutrino mass give systematic differences which are clearly detectable in the data. We recommend that these updated results be used when comparing cosmological constraints from WMAP, ACT and SPT with other surveys or with current and future full-mission Planck cosmology. Cosmological parameter chains are publicly available on the NASAs LAMBDA data archive.
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