We present an improved analysis of the final data set from the QUaD experiment. Using an improved technique to remove ground contamination, we double the effective sky area and hence increase the precision of our cosmic microwave background (CMB) power spectrum measurements by ∼30% versus that previously reported. In addition, we have improved our modeling of the instrument beams and have reduced our absolute calibration uncertainty from 5% to 3.5% in temperature. The robustness of our results is confirmed through extensive jackknife tests, and by way of the agreement that we find between our two fully independent analysis pipelines. For the standard six-parameter ΛCDM model, the addition of QUaD data marginally improves the constraints on a number of cosmological parameters over those obtained from the WMAP experiment alone. The impact of QUaD data is significantly greater for a model extended to include either a running in the scalar spectral index, or a possible tensor component, or both. Adding both the QUaD data and the results from the Arcminute Cosmology Bolometer Array Receiver experiment, the uncertainty in the spectral index running is reduced by ∼25% compared to WMAP alone, while the upper limit on the tensor-to-scalar ratio is reduced from r < 0.48 to r < 0.33 (95% c.l.). This is the strongest limit on tensors to date from the CMB alone. We also use our polarization measurements to place constraints on parity-violating interactions to the surface of last scattering, constraining the energy scale of Lorentz violating interactions to < 1.5×10 −43 GeV (68% c.l.). Finally, we place a robust upper limit on the strength of the lensing B-mode signal. Assuming a single flat band power between = 200 and = 2000, we constrain the amplitude of B-modes to be < 0.57 μK 2 (95% c.l.).

We report results from the second and third seasons of observation with the QUaD experiment. Angular power spectra of the cosmic microwave background are derived for both temperature and polarization at both 100 GHz and 150 GHz, and as cross-frequency spectra. All spectra are subjected to an extensive set of jackknife tests to probe for possible systematic contamination. For the implemented data cuts and processing technique such contamination is undetectable. We analyze the difference map formed between the 100 and 150 GHz bands and find no evidence of foreground contamination in polarization. The spectra are then combined to form a single set of results which are shown to be consistent with the prevailing LCDM model. The sensitivity of the polarization results is considerably better than that of any previous experimentfor the first time multiple acoustic peaks are detected in the E-mode power spectrum at high significance.

We constrain parity-violating interactions to the surface of last scattering using spectra from the QUaD experiment's second and third seasons of observations by searching for a possible systematic rotation of the polarization directions of CMB photons. We measure the rotation angle due to such a possible "cosmological birefringence" to be 0.55• (systematic) using QUaD's 100 and 150 GHz TB and EB spectra over the multipole range 200 < ℓ < 2000, consistent with null, and constrain Lorentz violating interactions to < 2 × 10 −43 GeV (68% confidence limit). This is the best constraint to date on electrodynamic parity violation on cosmological scales.

Anomalous microwave emission (AME) has been observed in numerous sky regions, using different experiments in the frequency range ∼ 10 − 60 GHz. One of the most scrutinized regions is G159.6-18.5, located within the Perseus molecular complex. In this paper we present further observations of this region (194 hours in total over ≈ 250 deg 2 ), both in intensity and in polarization. They span four independent frequency channels between 10 and 20 GHz, and were gathered with QUIJOTE, a new CMB experiment with the goal of measuring the polarization of the CMB and Galactic foregrounds. When combined with other publicly-available intensity data, we achieve the most precise spectrum of the AME measured to date in an individual region, with 13 independent data points between 10 and 50 GHz being dominated by this emission. The four QUIJOTE data points provide the first independent confirmation of the downturn of the AME spectrum at low frequencies, initially unveiled by the COSMOSOMAS experiment in this region. We accomplish an accurate fit of these data using models based on electric dipole emission from spinning dust grains, and also fit some of the parameters on which these models depend.We also present polarization maps with an angular resolution of ≈ 1 • and a sensitivity of ≈ 25 µK/beam. From these maps, which are consistent with zero polarization, we obtain upper limits of Π < 6.3% and < 2.8% (95% C.L.) respectively at 12 and 18 GHz, a frequency range where no AME polarization observations have been reported to date. These constraints are compatible with theoretical predictions of the polarization fraction from electric dipole emission originating from spinning dust grains. At the same time, they rule out several models based on magnetic dipole emission from dust grains ordered in a single magnetic domain, which typically predict higher polarization levels. Future QUIJOTE data in this region may allow more stringent constraints on the polarization level of the AME.

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