We perform a blind multi-component analysis of the WMAP 1 year foreground cleaned maps using SMICA (Spectral Matching Independent Component Analysis). We provide a new estimate of the CMB power spectrum as well as the amplitude of the CMB anisotropies across frequency channels. We show that the CMB anisotropies are compatible with temperature fluctuations as expected from the standard paradigm....

We describe an experiment to measure the polarization of the Cosmic Microwave Background (CMB) with the Degree Angular Scale Interferometer (DASI), a compact microwave interferometer optimized to detect CMB anisotropy at multipoles l ≃ 140 – 900. The telescope has operated at the Amundsen-Scott South Pole research station since 2000 January. The telescope was retrofit as a polarimeter during th...

We present measurements of the cosmic microwave background (CMB) power spectrum made by the Atacama Cosmology Telescope at 148 GHz and 218 GHz, as well as the cross-frequency spectrum between the two channels. Our results clearly show the second through the seventh acoustic peaks in the CMB power spectrum. The measurements of these higher-order peaks provide an additional test of the ΛCDM cosmo...

We discuss effects of cosmological moduli fields on the cosmic microwave background (CMB). If a modulus field φ once dominates the universe, the CMB we observe today is from the decay of φ and its anisotropy is affected by the primordial fluctuation in the amplitude of the modulus field. As a result, constraints on the inflaton potential from the CMB anisotropy can be relaxed. In addition, with...

Cosmic microwave background (CMB) studies underpin our understanding of the universe and its history. Until recently, we have relied principally on CMB temperature observations to build our standard cosmological model, but today the field forges ahead into its next frontier – CMB polarization anistropy. Polarization measurements will furnish fresh and independent information on the primordial d...

I present a series of diagrams which illustrate why the cosmic microwave background (CMB) data favor certain values for the cosmological parameters. Various methods to extract these parameters from CMB and non-CMB observations are forming an ever-tightening network of interlocking constraints. I review the increasingly precise constraints in the Ωm−ΩΛ plane and show why more cosmologists now pr...

The cosmic microwave background (CMB) is one of only a few physically observable remnants of the early Universe. Studies of the spectrum, polarization and spatial distribution of the CMB can potentially lead to a detailed understanding of the processes that took place in the early Universe. Many of the outstanding cosmological questions regarding the age, contents, future, and large scale dynam...

Application of a Goodness–of–fit (GOF) statistic is an essential element of parameter estimation. We discuss the computation of GOF when estimating parameters from anisotropy measurements of the cosmic microwave background (CMB), and we propose two GOF statistics to be used when employing approximate band– power likelihood functions. They are based on an approximate form for the distribution of...

I describe the imprint of primordial magnetic fields on the CMB. I show that these are observable only if the field amplitude is of the order of B & 10G on Mpc scale. I further argue that such fields are strongly constrained by the stochastic background of gravity waves which they produce. Primordial magnetic fields, which are strong enough to be seen in the CMB, are compatible with the nucleos...

Big-bang nucleosynthesis (BBN) and cosmic microwave background (CMB) anisotropy measurements give independent, accurate measurements of the baryon density and can test the framework of the standard cosmology. Early CMB data are consistent with the long-standing conclusion from BBN that baryons constitute a small fraction of matter in the Universe, but may indicate a slightly higher value for th...