Thesis (Ph. D.)--University of Chicago, Department of Physics, December 1999. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Chicago, Dept. of Physics, June 2003. / Includes bibliographical references. Also available on the Internet.

We study the consistency of 150 GHz data from the South Pole Telescope (SPT) and 143 GHz data from the Planck satellite over the patch of sky covered by the SPT-SZ survey. We first visually compare the maps and find that the residuals appear consistent with noise after accounting for differences in angular resolution and filtering. We then calculate (1) the cross-spectrum between two independent halves of SPT data, (2) the cross-spectrum between two independent halves of Planck data, and (3) the cross-spectrum between SPT and Planck data. We find that the three cross-spectra are well fit (PTE = 0.30) by the null hypothesis in which both experiments have measured the same sky map up to a single free calibration parameter-i.e., we find no evidence for systematic errors in either data set. As a by-product, we improve the precision of the SPT calibration by nearly an order of magnitude, from 2.6% to 0.3% in power. Finally, we compare all three cross-spectra to the full-sky Planck power spectrum and find marginal evidence for differences between the power spectra from the SPT-SZ footprint and the full sky. We model these differences as a power law in spherical harmonic multipole number. The best-fit value of this tilt is consistent among the three cross-spectra in the SPT-SZ footprint, implying that the source of this tilt is a sample variance fluctuation in the SPT-SZ region relative to the full sky. The consistency of cosmological parameters derived from these data sets is discussed in a companion paper.

We measure the cross-correlation between weak lensing of galaxy images and of the cosmic microwave background (CMB). The effects of gravitational lensing on different sources will be correlated if the lensing is caused by the same mass fluctuations. We use galaxy shape measurements from 139 deg(2) of the Dark Energy Survey (DES) Science Verification data and overlapping CMB lensing from the South Pole Telescope (SPT) and Planck. The DES source galaxies have a median redshift of z(med) similar to 0.7, while the CMB lensing kernel is broad and peaks at z similar to 2. The resulting cross-correlation is maximally sensitive to mass fluctuations at z similar to 0.44. Assuming the Planck 2015 best-fitting cosmology, the amplitude of the DESxSPT cross-power is found to be A(SPT) = 0.88 +/- 0.30 and that from DESxPlanck to be A(Planck) = 0.86 +/- 0.39, where A = 1 corresponds to the theoretical prediction. These are consistent with the expected signal and correspond to significances of 2.9 sigma and 2.2 sigma, respectively. We demonstrate that our results are robust to a number of important systematic effects including the shear measurement method, estimator choice, photo-z uncertainty and CMB lensing systematics. We calculate a value of A = 1.08 +/- 0.36 for DESxSPT when we correct the observations with a simple intrinsic alignment model. With three measurements of this cross-correlation now existing in the literature, there is not yet reliable evidence for any deviation from the expected LCDM level of cross-correlation. We provide forecasts for the expected signal-to-noise ratio of the combination of the five-year DES survey and SPT-3G.

In this thesis we examine the theoretical origin and statistical features of the Cosmic Microwave Background radiation. We particularly focus on the CMB power spectra and cosmological parameter estimation from QUaD CMB experiment data in order to derive implications for the concordance cosmological model. In chapter 4 we present a detailed parameter estimation analysis of the combined polarization and temperature power spectra from the second and third season observations of the QUaD experiment. QUaD has for the first time detected multiple acoustic peaks in the polarization spectrum, allowing meaningful parameter analyses from the polarization data alone. In a standard 6-parameter ACDM parameter estimation analysis we find the QUaD TT power spectrum to be in very good agreement with previous results. However, the QUaD polarization data shows some tension with ACDM model. The origin of this 1−2σ tension remains unclear, and may point to new physics, residual systematics or simple random chance. Combining polarization and temperature data we find an acceptable fit, and show that our results are dominated by the polarization signal. We combine QUaD with the five-year data from the WMAP satellite and the SDSS Luminous Red Galaxies 4th data release power spectrum, and extend our analysis to constrain the tensor-to-scalar ratio and the primordial isocurvature perturbations. Our analysis sets a benchmark for future polarization experiments. In chapter 5 we outline and test a new semi-analytical approach for the estimation of the pseudo- temperature and polarization CMB power spectra for experiments with incomplete sky coverage. We propose a method for constructing the mode-mode coupling matrices which connect the temperature and polarization pseudo-Cℓ’s to the unbiased all-sky bandpowers in the flat sky approximation. We apply this method to the apodization masks of the QUaD CMB experiment and we show that the true underlying bandpowers can be reconstructed from the simulated QUaD-like pseudo-Cℓ’s to high precision. We further investigate the possibility of extending the proposed analytical flat sky approach to the exact calculation of the PCL covariance matrices over a large range of multipoles and we find that the numerical calculation is extremely computationally expensive. The flat sky pseudo-Cℓ and covariances methods presented in this chapter are still work in progress and require more testing.

We detect the kinematic Sunyaev-Zel'dovich (kSZ) effect with a statistical significance of 4.2 sigma by combining a cluster catalogue derived from the first year data of the Dark Energy Survey with cosmic microwave background temperature maps from the South Pole Telescope Sunyaev-Zel'dovich Survey. This measurement is performed with a differential statistic that isolates the pairwise kSZ signal, providing the first detection of the large-scale, pairwise motion of clusters using redshifts derived from photometric data. By fitting the pairwise kSZ signal to a theoretical template, we measure the average central optical depth of the cluster sample, (tau) over bar (e) = (3.75 +/- 0.89) x 10(-3). We compare the extracted signal to realistic simulations and find good agreement with respect to the signal to noise, the constraint on (tau) over bar (e), and the corresponding gas fraction. High-precision measurements of the pairwise kSZ signal with future data will be able to place constraints on the baryonic physics of galaxy clusters, and could be used to probe gravity on scales greater than or similar to 100 Mpc.

>Magister Scientiae - MSc / Public concern about all radiation and radon exhalation from building materials has been highlighted recently. The purpose of this study is to address this public concern and to investigate the contribution of building materials to indoor radon levels. As in soil and rocks, radon gas is formed inside the building materials by decay of the parent nuclide 226Ra. It is not possible to determine the radon exhalation rate simply from the activity concentration of 226Ra, instead one must measure radon exhalation rates directly from the surface of the material. 222Rn has been identified as an important factor that could result in a health hazard by studies all around the world. The exhalation experiments were done at the UWC physics department, in the Nuclear Physics Lab. A RAD7 radon detector was used to measure the radon concentration in an air tight chamber that contained various building material samples. The RAD7 records the number of alpha particles with energy of 6.11 MeV which results from the decay of 218Po, the daughter of 222Rn. The RAD7 detector converts counts into Becquerel’s per cubic metre (Bq/m3). The building materials tested were the raw materials used in construction such as two different types of building sand, building stones, coarse aggregate, floor and roof tiles, various granites from across the world that were sourced locally and uranium bearing sandstone originating from a Beaufort-West prospecting site. Stones from this site were used as filler material in the construction of two farm houses. Most building materials were found to have a very low rate of radon exhalation. The only materials that had any significant radon exhalation were 2 granite samples with a maximum exhalation rate of 1.5 Bq.m-2.h-1 and the uranium bearing sandstone. It is safe to say that the overwhelming majority of building materials tested are safe to use but some granites may require further study. The uranium bearing sandstone is a definite radiation protection issue and should not be used in any construction.

Lau, King = 普朗克衛星測量對純量-張量比例的規範 / 劉荊. / Thesis M.Phil. Chinese University of Hong Kong 2013. / Includes bibliographical references (leaves 83-89). / Abstracts also in Chinese. / Title from PDF title page (viewed on 15, September, 2016). / Lau, King = Pulangke wei xing ce liang dui chun liang-zhang liang bi li de gui fan / Liu Jing.

This thesis investigates weak lensing (WL) of galaxies and the cosmic microwave back- ground (CMB) in the nonlinear regime. WL describes the effect of bending of background light rays by foreground matter (“lens”). It is sensitive to the large scale structure of the universe, and hence is a promising method to answer some unsolved fundamental questions in physics, such as the nature of dark energy and the total mass of neutrinos. WL datasets of unprecedented precision will come on-line in the early 2020s. This presents an exciting yet challenging task for the WL community: how do we extract the maximum amount of information from lensing observables, while minimizing the impact of systematics? This work attempts to answer this question by studying non-Gaussian statistics. Traditionally, WL data are analyzed using second-order statistics, which capture all the cosmological information if the density field is Gaussian. However, the small-scale density fluctuations are strongly non-Gaussian and can be highly sensitive to cosmology. Thus we need higher order (non-Gaussian) statistics to utilize these features in the nonlinear regime. In this thesis, we study the constraining power on cosmology and relevant systematics of non-Gaussian statistics, with a focus on convergence peaks. We present the first cosmological constraints using peak counts of the CFHTLenS survey. We also quantify the impact of magnification and size bias, one type of lensing systematics, on the lensing power spectrum and peaks. Finally, going beyond galaxy lensing, we cross-correlate Planck CMB lensing maps with CFHTLenS galaxy lensing maps, to investigate various WL systematics.

The E and B EXperiment (EBEX) is a pointed balloon-borne telescope designed to measure the polarization of the cosmic microwave background (CMB) as well as that from Galactic dust. The instrument is equipped with a 1.5 meter aperture Gregorian-Dragone telescope, providing an 8' beam at three frequency bands centered on 150, 250 and 410 GHz. The telescope is designed to measure or place an upper limit on inflationary B-mode signals and to probe B-modes originating from gravitationnal lensing of the CMB. The higher EBEX frequencies are designed to enable the measurement and removal of polarized Galactic dust foregrounds which currently limit the measurement of inflationary B-modes. Polarimetry is achieved by rotating an achromatic half-wave plate (HWP) on a superconducting magnetic bearing. In January 2013, EBEX completed 11 days of observations in a flight over Antarctica covering 6,000 square degrees of the southern sky. This marks the first time that kilo-pixel TES bolometer arrays have made science observations on a balloon-borne platform. In this thesis we report on the construction, deployment and data analysis of EBEX. We review the development of the pointing sensors and software used for real-time attitude determination and control, including pre-flight testing and calibration. We then report on the 2013 long duration flight (LD2013) and review all the major stages of the analysis pipeline used to transform the ~1 TB of raw data into polarized sky maps. We review "LEAP", the software framework developed to support the analysis pipeline. We discuss in detail the novel program developed to reconstruct the attitude post-flight and estimate the effect of attitude errors on measured B-mode signals. We describe the bolometer time-stream cleaning procedure including removing the HWP-synchronous signal, and we detail the map making procedure. Finally we present a novel method to measure and subtract instrumental polarization, after which we show Galaxy and CMB maps.