Constraints on Dark Matter Properties from Observations of Milky Way Satellite Galaxies.

We perform a comprehensive study of Milky Way (MW) satellite galaxies to constrain the fundamental properties of dark matter (DM). This analysis fully incorporates inhomogeneities in the spatial distribution and detectability of MW satellites and marginalizes over uncertainties in the mapping between galaxies and DM halos, the properties of the MW system, and the disruption of subhalos by the MW disk. Our results are consistent with the cold, collisionless DM paradigm and yield the strongest cosmological constraints to date on particle models of warm, interacting, and fuzzy dark matter. At 95% confidence, we report limits on (i) the mass of thermal relic warm DM, m_{WDM}>6.5 keV (free-streaming length, λ_{fs}≲10h^{-1} kpc), (ii) the velocity-independent DM-proton scattering cross section, σ_{0}<8.8×10^{-29} cm^{2} for a 100 MeV DM particle mass [DM-proton coupling, c_{p}≲(0.3 GeV)^{-2}], and (iii) the mass of fuzzy DM, m_{ϕ}>2.9×10^{-21} eV (de Broglie wavelength, λ_{dB}≲0.5 kpc). These constraints are complementary to other observational and laboratory constraints on DM properties.

Detection of CMB-Cluster Lensing using Polarization Data from SPTpol.

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500 deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.

Wide-Field Lensing Mass Maps from Dark Energy Survey Science Verification Data.

We present a mass map reconstructed from weak gravitational lensing shear measurements over 139 deg2 from the Dark Energy Survey science verification data. The mass map probes both luminous and dark matter, thus providing a tool for studying cosmology. We find good agreement between the mass map and the distribution of massive galaxy clusters identified using a red-sequence cluster finder. Potential candidates for superclusters and voids are identified using these maps. We measure the cross-correlation between the mass map and a magnitude-limited foreground galaxy sample and find a detection at the 6.8σ level with 20 arc min smoothing. These measurements are consistent with simulated galaxy catalogs based on N-body simulations from a cold dark matter model with a cosmological constant. This suggests low systematics uncertainties in the map. We summarize our key findings in this Letter; the detailed methodology and tests for systematics are presented in a companion paper.

Constraints on galaxy bias, matter density, and primordial non-Gaussianity from the PSCz galaxy redshift survey.

We compute the bispectrum for the IRAS PSCz catalog and find that the galaxy distribution displays the characteristic signature of gravity. Assuming Gaussian initial conditions, we obtain galaxy biasing parameters 1/b(1) = 1.20(+0.18)(-0.19) and b(2)/b(2)(1) = -0.42+/-0.19, with no sign of scale-dependent bias for k < or = 0.3h Mpc(-1). These results impose stringent constraints on non-Gaussian initial conditions. For dimensional scaling models with chi(2)(N) statistics, we find N > 49, which implies a constraint on primordial skewness B3 < 0.35.

Weak Gravitational Lensing by the Nearby Cluster Abell 3667.

We present two weak lensing reconstructions of the nearby (zcl=0.055) merging cluster Abell 3667, based on observations taken approximately 1 yr apart under different seeing conditions. This is the lowest redshift cluster with a weak lensing mass reconstruction to date. The reproducibility of features in the two mass maps demonstrates that weak lensing studies of low-redshift clusters are feasible. These data constitute the first results from an X-ray luminosity-selected weak lensing survey of 19 low-redshift (z<0.1) southern clusters.

Comparison of three procedures in reducing self-injurious behavior.

In the present study the effects of withdrawal of food, withdrawal of attention, and the simultaneous withdrawal of food and attention on the rate of self-injurious behavior of three profoundly retarded girls during mealtime were investigated. The two treatments that prevented eating led to a marked reduction of self-injurious behavior. Application of the method allowing continuation of eating (withdrawal of attention) resulted in an increased rate of two subjects' self-injurious behavior and had little effect on the rate of self-injurious behavior of the third. An analysis of the data suggests that contingent interruption of meal consumption can reduce the behavior and that rates of self-injurious behavior vary as a result of reinforcement.