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de Putter, R., Verde, L., & Jimenez, R. (2013). Testing LTB void models without the cosmic microwave background or large scale structure: new constraints from galaxy ages. J. Cosmol. Astropart. Phys., 02(2), 047–22pp.
Abstract: We present new observational constraints on inhomogenous models based on observables independent of the CMB and large-scale structure. Using Bayesian evidence we find very strong evidence for homogeneous LCDM model, thus disfavouring inhomogeneous models. Our new constraints are based on quantities independent of the growth of perturbations and rely on cosmic clocks based on atomic physics and on the local density of matter.
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Manera, M., Scoccimarro, R., Percival, W. J., Samushia, L., McBride, C. K., Ross, A. J., et al. (2013). The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: a large sample of mock galaxy catalogues. Mon. Not. Roy. Astron. Soc., 428(2), 1036–1054.
Abstract: We present a fast method for producing mock galaxy catalogues that can be used to compute the covariance of large-scale clustering measurements and test analysis techniques. Our method populates a second-order Lagrangian perturbation theory (2LPT) matter field, where we calibrate masses of dark matter haloes by detailed comparisons with N-body simulations. We demonstrate that the clustering of haloes is recovered at similar to 10 per cent accuracy. We populate haloes with mock galaxies using a halo occupation distribution (HOD) prescription, which has been calibrated to reproduce the clustering measurements on scales between 30 and 80 h(-1) Mpc. We compare the sample covariance matrix from our mocks with analytic estimates, and discuss differences. We have used this method to make catalogues corresponding to Data Release 9 of the Baryon Oscillation Spectroscopic Survey (BOSS), producing 600 mock catalogues of the 'CMASS' galaxy sample. These mocks have enabled detailed tests of methods and errors, and have formed an integral part of companion analyses of these galaxy data.
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Giusarma, E., de Putter, R., Ho, S., & Mena, O. (2013). Constraints on neutrino masses from Planck and Galaxy clustering data. Phys. Rev. D, 88(6), 063515–9pp.
Abstract: We present here bounds on neutrino masses from the combination of recent Planck cosmic microwave background (CMB) measurements and galaxy clustering information from the Baryon Oscillation Spectroscopic Survey, part of the Sloan Digital Sky Survey-III. We use the full shape of either the photometric angular clustering (Data Release 8) or the 3D spectroscopic clustering (Data Release 9) power spectrum in different cosmological scenarios. In the Lambda CDM scenario, spectroscopic galaxy clustering measurements improve significantly the existing neutrino mass bounds from Planck data. We find Sigma m(v) < 0.39 eV at 95% confidence level for the combination of the 3D power spectrum with Planck CMB data (wi lensing included) and Wilkinson Microwave Anisoptropy Probe 9-year polarization measurements. Therefore, robust neutrino mass constraints can be obtained without the addition of the prior on the Hubble constant from Hubble Space Telescope. In extended cosmological scenarios with a dark energy fluid or with nonflat geometries, galaxy clustering measurements are essential to pin down the neutrino mass bounds, providing in the majority of cases better results than those obtained from the associated measurement of the baryon acoustic oscillation scale only. In the presence of a freely varying (constant) dark energy equation of state, we find Sigma m(v) < 0.49 eV at 95% confidence level for the combination of the 3D power spectrum with Planck CMB data (with lensing included) and Wilkinson Microwave Anisoptropy Probe 9-year polarization measurements. This same data combination in nonflat geometries provides the neutrino mass bound Sigma m(v) < 0.35 eV at 95% confidence level.
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Giusarma, E., Corsi, M., Archidiacono, M., de Putter, R., Melchiorri, A., Mena, O., et al. (2011). Constraints on massive sterile neutrino species from current and future cosmological data. Phys. Rev. D, 83(11), 115023–10pp.
Abstract: Sterile massive neutrinos are a natural extension of the standard model of elementary particles. The energy density of the extra sterile massive states affects cosmological measurements in an analogous way to that of active neutrino species. We perform here an analysis of current cosmological data and derive bounds on the masses of the active and the sterile neutrino states, as well as on the number of sterile states. The so-called (3 + 2) models, with three sub-eV active massive neutrinos plus two sub-eV massive sterile species, is well within the 95% CL allowed regions when considering cosmological data only. If the two extra sterile states have thermal abundances at decoupling, big bang nucleosynthesis bounds compromise the viability of (3 + 2) models. Forecasts from future cosmological data on the active and sterile neutrino parameters are also presented. Independent measurements of the neutrino mass from tritium beta-decay experiments and of the Hubble constant could shed light on sub-eV massive sterile neutrino scenarios.
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