We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400 deg 2 patch of sky centered on RA 0 h, Dec. −57.5°. The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2 μK deg in Q and U at 143 GHz). We detect 150 × 353 cross-correlation in B modes at high significance. We fit the single-and cross-frequency power spectra at frequencies ≥ 150 GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r 0.05 < 0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0σ significance.

We present results from an analysis of all data taken by the BICEP2 and Keck Array cosmic microwave background (CMB) polarization experiments up to and including the 2014 observing season. This includes the first Keck Array observations at 95 GHz. The maps reach a depth of 50 nK deg in Stokes Q and U in the 150 GHz band and 127 nK deg in the 95 GHz band. We take auto-and cross-spectra between these maps and publicly available maps from WMAP and Planck at frequencies from 23 to 353 GHz. An excess over lensed ΛCDM is detected at modest significance in the 95 × 150 BB spectrum, and is consistent with the dust contribution expected from our previous work. No significant evidence for synchrotron emission is found in spectra such as 23 × 95, or for correlation between the dust and synchrotron sky patterns in spectra such as 23 × 353. We take the likelihood of all the spectra for a multicomponent model including lensed ΛCDM, dust, synchrotron, and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r) using priors on the frequency spectral behaviors of dust and synchrotron emission from previous analyses of WMAP and Planck data in other regions of the sky. This analysis yields an upper limit r 0.05 < 0.09 at 95% confidence, which is robust to variations explored in analysis and priors. Combining these B-mode results with the (more model-dependent) constraints from Planck analysis of CMB temperature plus baryon acoustic oscillations and other data yields a combined limit r 0.05 < 0.07 at 95% confidence. These are the strongest constraints to date on inflationary gravitational waves. DOI: 10.1103/PhysRevLett.116.031302 PRL 116, 031302 (2016) P H Y S I C A L R E V I E W L E T T E R S week ending 22 JANUARY 20160031-9007=16=116(3)=031302 (9) 031302-1 © 2016 American Physical SocietyIntroduction.-Measurements of the cosmic microwave background (CMB) [1] are one of the observational pillars of the standard cosmological model (ΛCDM) and constrain its parameters to high precision (see most recently Ref. [2]). This model extrapolates the Universe back to very high temperatures (≫10 12 K) and early times (≪ 1 s). Observations indicate that conditions at these early times are described by an almost uniform plasma with a nearly scale invariant spectrum of adiabatic density perturbations. However, ΛCDM itself offers no explanation for how these conditions occurred. The theory of inflation is an extension to the standard model, which postulates a phase of exponential expansion at a still earlier epoch (∼10 −35 s) that precedes ΛCDM and produces the required initial conditions (see Ref.[3] for a recent review and citations to the original literature).There is widespread support for the claim that existing observations already indicate that some version of inflation probably did occur, but there are also skeptics [4,5]. As well as the specific form of the initial density perturbations, there is an additional relic which inflation predicts, and which one can attempt to detect....

Using the Atacama Large Millimeter/submillimeter Array, we have conducted a blind redshift survey in the 3 mm atmospheric transmission window for 26 strongly lensed dusty star-forming galaxies (DSFGs) selected with the South Pole Telescope. The sources were selected to have S 1.4 mm > 20 mJy and a dust-like spectrum and, to remove low-z sources, not have bright radio (S 843 MHz < 6 mJy) or far-infrared counterparts (S 100 μm < 1 Jy, S 60 μm < 200 mJy). We robustly detect 44 line features in our survey, which we identify as redshifted emission lines of 12 CO, 13 CO, C i, H 2 O, and H 2 O +. We find one or more spectral features in 23 sources yielding a ∼90% detection rate for this survey; in 12 of these sources we detect multiple lines, while in 11 sources we detect only a single line. For the sources with only one detected line, we break the redshift degeneracy with additional spectroscopic observations if available, or infer the most likely line identification based on photometric data. This yields secure redshifts for ∼70% of the sample. The three sources with no lines detected are tentatively placed in the redshift desert between 1.7 < z < 2.0. The resulting mean redshift of our sample isz = 3.5. This finding is in contrast to the redshift distribution of radio-identified DSFGs, which have a significantly lower mean redshift ofz = 2.3 and for which only 10%-15% of the population is expected to be at z > 3. We discuss the effect of gravitational

The South Pole Telescope (SPT) is a 10 m diameter, wide-field, offset Gregorian telescope with a 966-pixel, multi-color, millimeter-wave, bolometer camera. It is located at the Amundsen-Scott South Pole station in Antarctica. The design of the SPT emphasizes careful control of spillover and scattering, to minimize noise and false signals due to ground pickup. The key initial project is a large-area survey at wavelengths of 3, 2 and 1.3 mm, to detect clusters of galaxies via the Sunyaev-Zeldovich effect and to measure the small-scale angular power spectrum of the cosmic microwave background (CMB). The data will be used to characterize the primordial matter power spectrum and to place constraints on the equation of state of dark energy. A second-generation camera will measure the polarization of the CMB, potentially leading to constraints on the neutrino mass and the energy scale of inflation.Comment: 47 pages, 14 figures, updated to match version to be published in PASP 123 903 (May, 2011

We present results from an analysis of all data taken by the BICEP2/Keck CMB polarization experiments up to and including the 2015 observing season. This includes the first Keck Array observations at 220 GHz and additional observations at 95 & 150 GHz. The Q/U maps reach depths of 5.2, 2.9 and 26 µKcmb arcmin at 95, 150 and 220 GHz respectively over an effective area of ≈ 400 square degrees. The 220 GHz maps achieve a signal-to-noise on polarized dust emission approximately equal to that of Planck at 353 GHz. We take auto-and cross-spectra between these maps and publicly available WMAP and Planck maps at frequencies from 23 to 353 GHz. We evaluate the joint likelihood of the spectra versus a multicomponent model of lensed-ΛCDM+r+dust+synchrotron+noise. The foreground model has seven parameters, and we impose priors on some of these using external information from Planck and WMAP derived from larger regions of sky. The model is shown to be an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r0.05 < 0.07 at 95% confidence, which tightens to r0.05 < 0.06 in conjunction with Planck temperature measurements and other data. The lensing signal is detected at 8.8σ significance. Running maximum likelihood search on simulations we obtain unbiased results and find that σ(r) = 0.020. These are the strongest constraints to date on primordial gravitational waves.