We show that clusters of galaxies induce step-like wiggles on top of the cosmic microwave background (CMB). The direction of the wiggle is parallel to the large scale gradient of CMB allowing one to isolate the effect from other small scale fluctuations. The effect is sensitive to the deflection angle rather than its derivative (shear or magnification) and is thus tracing outer parts of the clu...

We report on the design, first observing season, and analysis of data from a new prototype millimeterwave interferometer, MINT. MINT consists of four 145GHz SIS mixers operating in double-sideband mode in a compact heterogeneous configuration. The signal band is subdivided by a monolithic channelizer, after which the correlations between antennas are performed digitally. The typical receiver se...

The Cosmic Microwave Background Radiation (CMB) is an invaluable probe of the conditions of the early universe. Recent measurements of its spatial anisotropy have allowed accurate determinations of several fundamental cosmological parameters, such as the curvature of the universe, the shape of the spectrum of primordial density fluctuations, and the contribution of baryons, dark matter, and dar...

In the inflation cosmic models, the relic gravitational waves (RGW) generated in the inflation stage, and evolved in the universe until now. In the different cosmic evolution models, one can get different gravitational waves spectrum. In this paper, we give a simple formula to estimate the spectrum in a general cosmic model. From this spectrum, one can easily find the relation between the RGW s...

We present a simple, yet accurate approximation for calculating the cosmic microwave background anisotropy power spectrum in adiabatic models. It consists of solving for the evolution of a two-fluid model until the epoch of recombination and then integrating over the sources to obtain the CMB anisotropy power spectrum. The approximation is useful both for a physical understanding of CMB anisotr...

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...

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...

The next generation low-frequency radio telescopes may probe cosmological models by means of observations of the cosmic microwave background (CMB). I discuss the prospects for observations of CMB imprints — recombination lines from the epoch of recombination, μ distortions and angular temperature anisotropies — at low frequencies. A future low-frequency radio telescope, like the proposed SKA, m...

We revisit the constraint on the primordial helium mass fraction Yp from observations of cosmic microwave background (CMB) alone. By minimizing χ of recent CMB experiments over 6 other cosmological parameters, we obtained rather weak constraints as 0.17 ≤ Yp ≤ 0.52 at 1σ C.L. for a particular data set. We also study the future constraint on cosmological parameters when we take account of the pr...

The Cosmic Microwave Background Radiation (CMB) is an invaluable probe of the conditions of the early universe. Recent measurements of its spatial anisotropy have allowed accurate determinations of several fundamental cosmological parameters, such as the curvature of the universe, the shape of the spectrum of primordial density fluctuations, and the contribution of baryons, dark matter, and dar...