The Baryon Oscillation Spectroscopic Survey (BOSS) has collected spectra for over one million galaxies at $0.15<z<0.7$ over a volume of 15.3 Gpc$^3$ (9,376 deg$^2$) -- providing us an opportunity to study the most massive galaxy populations with vani
shing sample variance. However, BOSS samples are selected via complex color cuts that are optimized for cosmology studies, not galaxy science. In this paper, we supplement BOSS samples with photometric redshifts from the Stripe 82 Massive Galaxy Catalog and measure the total galaxy stellar mass function (SMF) at $zsim0.3$ and $zsim0.55$. With the total SMF in hand, we characterize the stellar mass completeness of BOSS samples. The high-redshift CMASS (constant mass) sample is significantly impacted by mass incompleteness and is 80% complete at $log_{10}(M_*/M_{odot}) >11.6$ only in the narrow redshift range $z=[0.51,0.61]$. The low redshift LOWZ sample is 80% complete at $log_{10}(M_*/M_{odot}) >11.6$ for $z=[0.15,0.43]$. To construct mass complete samples at lower masses, spectroscopic samples need to be significantly supplemented by photometric redshifts. This work will enable future studies to better utilize the BOSS samples for galaxy-formation science.
Understanding the relation between underlying matter distribution and biased tracers such as galaxy or dark matter halo is essential to extract cosmological information from ongoing or future galaxy redshift surveys. At sufficiently large scales such
as the BAO scale, a standard approach for the bias problem on the basis of the perturbation theory (PT) is to assume the `local bias model in which the density field of biased tracers is deterministically expanded in terms of matter density field at the same position. The higher-order bias parameters are then determined by combining the power spectrum with higher-order statistics such as the bispectrum. As is pointed out by recent studies, however, nonlinear gravitational evolution naturally induces nonlocal bias terms even if initially starting only with purely local bias. As a matter of fact, previous works showed that the second-order nonlocal bias term, which corresponds to the gravitational tidal field, is important to explain the characteristic scale-dependence of the bispectrum. In this paper we extend the nonlocal bias term up to third order, and investigate whether the PT-based model including nonlocal bias terms can simultaneously explain the power spectrum and the bispectrum of simulated halos in $N$-body simulations. We show that the power spectrum, including density and momentum, and the bispectrum between halo and matter in $N$-body simulations can be simultaneously well explained by the model including up to third-order nonlocal bias terms up to k~0.1h/Mpc. Also, the results seem in a good agreement with theoretical predictions of a simple coevolution picture, although the agreement is not perfect. These demonstration clearly shows a failure of the local bias model even at such large scales, and we conclude that nonlocal bias terms should be consistently included in order to model statistics of halos. [abridged]
We investigate the cosmological implications of the latest growth of structure measurement from the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS Data Release 11 with particular focus on the sum of the neutrino masses, $sum m_{ u}$. We examine
the robustness of the cosmological constraints from the Baryon Acoustic Oscillation (BAO) scale, the Alcock-Paczynski effect and redshift-space distortions ($D_V/r_s$, $F_{rm AP}$, $fsigma_8$) of citet{Beutler:2013b}, when introducing a neutrino mass in the power spectrum template. We then discuss how the neutrino mass relaxes discrepancies between the Cosmic Microwave Background (CMB) and other low-redshift measurements within $Lambda$CDM. Combining our cosmological constraints with WMAP9 yields $sum m_{ u} = 0.36pm0.14,$eV ($68%$ c.l.), which represents a $2.6sigma$ preference for non-zero neutrino mass. The significance can be increased to $3.3sigma$ when including weak lensing results and other BAO constraints, yielding $sum m_{ u} = 0.35pm0.10,$eV ($68%$ c.l.). However, combining CMASS with Planck data reduces the preference for neutrino mass to $sim 2sigma$. When removing the CMB lensing effect in the Planck temperature power spectrum (by marginalising over $A_{rm L}$), we see shifts of $sim 1sigma$ in $sigma_8$ and $Omega_m$, which have a significant effect on the neutrino mass constraints. In case of CMASS plus Planck without the $A_{rm L}$-lensing signal, we find a preference for a neutrino mass of $sum m_{ u} = 0.34pm 0.14,$eV ($68%$ c.l.), in excellent agreement with the WMAP9+CMASS value. The constraint can be tightened to $3.4sigma$ yielding $sum m_{ u} = 0.36pm 0.10,$eV ($68%$ c.l.) when weak lensing data and other BAO constraints are included.
We analyse the anisotropic clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS Data Release 11 (DR11) sample, which consists of $690,827$ galaxies in the redshift range $0.43 < z < 0.7$ and has a sky coverage of $8,498,text{deg}^2$
. We perform our analysis in Fourier space using a power spectrum estimator suggested by Yamamoto et al. (2006). We measure the multipole power spectra in a self-consistent manner for the first time in the sense that we provide a proper way to treat the survey window function and the integral constraint, without the commonly used assumption of an isotropic power spectrum and without the need to split the survey into sub-regions. The main cosmological signals exploited in our analysis are the Baryon Acoustic Oscillations and the signal of redshift space distortions, both of which are distorted by the Alcock-Paczynski effect. Together, these signals allow us to constrain the distance ratio $D_V(z_{rm eff})/r_s(z_d) = 13.89pm 0.18$, the Alcock-Paczynski parameter $F_{rm AP}(z_{rm eff}) = 0.679pm0.031$ and the growth rate of structure $f(z_{rm eff})sigma_8(z_{rm eff}) = 0.419pm0.044$ at the effective redshift $z_{rm eff}=0.57$. We did not find significant systematic uncertainties for $D_V/r_s$ or $F_{rm AP}$ but include a systematic error for $fsigma_8$ of $3.1%$. Combining our dataset with Planck to test General Relativity (GR) through the simple $gamma$-parameterisation, reveals a $sim 2sigma$ tension between the data and the prediction by GR. The tension between our result and GR can be traced back to a tension in the clustering amplitude $sigma_8$ between CMASS and Planck.
We measure the sum of the neutrino particle masses using the three-dimensional galaxy power spectrum of the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 9 (DR9) CMASS galaxy sample. Combined with the cosmic microwave backgroun
d (CMB), supernova (SN) and additional baryonic acoustic oscillation (BAO) data, we find upper 95 percent confidence limits of the neutrino mass $Sigma m_{ u}<0.340$ eV within a flat $Lambda$CDM background, and $Sigma m_{ u}<0.821$ eV, assuming a more general background cosmological model. The number of neutrino species is measured to be $N_{rm eff}=4.308pm0.794$ and $N_{rm eff}=4.032^{+0.870}_{-0.894}$ for these two cases respectively. We study and quantify the effect of several factors on the neutrino measurements, including the galaxy power spectrum bias model, the effect of redshift-space distortion, the cutoff scale of the power spectrum, and the choice of additional data. The impact of neutrinos with unknown masses on other cosmological parameter measurements is investigated. The fractional matter density and the Hubble parameter are measured to be $Omega_M=0.2796pm0.0097$, $H_0=69.72^{+0.90}_{-0.91}$ km/s/Mpc (flat $Lambda$CDM) and $Omega_M=0.2798^{+0.0132}_{-0.0136}$, $H_0=73.78^{+3.16}_{-3.17}$ km/s/Mpc (more general background model). Based on a Chevallier-Polarski-Linder (CPL) parametrisation of the equation-of-state $w$ of dark energy, we find that $w=-1$ is consistent with observations, even allowing for neutrinos. Similarly, the curvature Omega_K and the running of the spectral index $alpha_s$ are both consistent with zero. The tensor-to-scaler ratio is constrained down to $r<0.198$ (95 percent CL, flat $Lambda$ CDM) and $r<0.440$ (95 percent CL, more general background model).
We compare the model power spectrum, computed based on perturbation theory (PT) with the power spectrum of luminous red galaxies (LRG) measured from the SDSSDR7 catalog, assuming a flat, CDM-dominated cosmology. The model includes the effects of mass
ive neutrinos, nonlinear matter clustering and nonlinear, scale-dependent galaxy bias in a self-consistent manner. We first test the accuracy of PT-model by comparing the model predictions with the halo power spectrum in real- and redshift-space measured from simulations without massive neutrinos. We show that the PT-model with bias parameters being properly adjusted can fairly well reproduce the simulation results. As a result the best-fit parameters obtained from the hypothetical parameter fitting recover, within statistical uncertainties, the input cosmological parameters in simulations, including an upper bound on neutrino mass, if the power spectrum information up to k~0.15h/Mpc is used. However, for the redshift-space power spectrum, the best-fit cosmological parameters show a sizable bias from the input values if using the information up to k~0.2h/Mpc, probably due to nonlinear redshift distortion effect. Given these tests, we decided, as a conservative choice, to use the LRG power spectrum up to k=0.1h/Mpc in order to minimize possible unknown nonlinearity effects. In combination with the recent results from Wilkinson Microwave Background Anisotropy Probe (WMAP), we derive a robust upper-bound on the sum of neutrino masses, given as m_nu,tot < 0.81eV (95% C.L.), marginalized over other parameters including nonlinear bias parameters and dark energy equation of state parameter. The neutrino mass limit is improved by a factor of 1.85 compared to the limit from the WMAP5 alone, m_nu,tot < 1.5eV.
Future or ongoing galaxy redshift surveys can put stringent constraints on neutrinos masses via the high-precision measurements of galaxy power spectrum, when combined with cosmic microwave background (CMB) information. In this paper we develop a met
hod to model galaxy power spectrum in the weakly nonlinear regime for a mixed dark matter (CDM plus finite-mass neutrinos) model, based on perturbation theory (PT) whose validity is well tested by simulations for a CDM model. In doing this we carefully study various aspects of the nonlinear clustering and then arrive at a useful approximation allowing for a quick computation of the nonlinear power spectrum as in the CDM case. The nonlinear galaxy bias is also included in a self-consistent manner within the PT framework. Thus the use of our PT model can give a more robust understanding of the measured galaxy power spectrum as well as allow for higher sensitivity to neutrino masses due to the gain of Fourier modes beyond the linear regime. Based on the Fisher matrix formalism, we find that BOSS or Stage-III type survey, when combined with Planck CMB information, gives a precision of total neutrino mass constraint, sigma(m_nu,tot) 0.1eV, while Stage-IV type survey may achieve sigma(m_nu,tot) 0.05eV, i.e. more than a 1-sigma detection of neutrino masses. We also discuss possible systematic errors on dark energy parameters caused by the neutrino mass uncertainty. The significant correlation between neutrino mass and dark energy parameters is found, if the information on power spectrum amplitude is included. More importantly, for Stage-IV type survey, a best-fit dark energy model may be biased and falsely away from the underlying true model by more than the 1-sigma statistical errors, if neutrino mass is ignored in the model fitting.
We present the first attempt to analytically study the nonlinear matter power spectrum for a mixed dark matter (cold dark matter plus neutrinos of total mass ~0.1eV) model based on cosmological perturbation theory. The suppression in the power spectr
um amplitudes due to massive neutrinos is, compared to the linear regime, enhanced in the weakly nonlinear regime where standard linear theory ceases to be accurate. We demonstrate that, thanks to this enhanced effect and the gain in the range of wavenumbers to which the PT prediction is applicable, the use of such a nonlinear model may enable a precision of sigma(m_nu,tot) ~ 0.07eV in constraining the total neutrino mass for the planned galaxy redshift survey, a factor of 2 improvement compared to the linear regime.
We discuss the polarization signature of primordial gravitational waves imprinted in cosmic microwave background (CMB) anisotropies. The high-energy physics motivated by superstring theory or M-theory generically yield parity violating terms, which m
ay produce a circularly polarized gravitational wave background (GWB) during inflation. In contrast to the standard prediction of inflation with un-polarized GWB, circularly polarized GWB generates non-vanishing TB and EB-mode power spectra of CMB anisotropies. We evaluate the TB and EB-mode power spectra taking into account the secondary effects and investigate the dependence of cosmological parameters. We then discuss current constraints on the circularly polarized GWB from large angular scales (l < 16) of the three year WMAP data. Prospects for future CMB experiments are also investigated based on a Monte Carlo analysis of parameter estimation, showing that the circular polarization degree, varepsilon, which is the asymmetry of the tensor power spectra between right- and left-handed modes normalized by the total amplitude, can be measured down to |varepsilon| 0.35(r/0.05)^{-0.6}.
