F. Melchiorri

Measurement of a Peak in the Cosmic Microwave Background Power Spectrum from the North American Test Flight of Boomerang

We describe a measurement of the angular power spectrum of anisotropies in the cosmic microwave background (CMB) at scales of 0&fdg;3 to 5 degrees from the North American test flight of the Boomerang experiment. Boomerang is a balloon-borne telescope with a bolometric receiver designed to map CMB anisotropies on a long-duration balloon flight. During a 6 hr test flight of a prototype system in 1997, we mapped more than 200 deg(2) at high Galactic latitudes in two bands centered at 90 and 150 GHz with a resolution of 26&arcmin; and 16&farcm;5 FWHM, respectively. Analysis of the maps gives a power spectrum with a peak at angular scales of 1 degrees with an amplitude 70 µK(CMB).

Cosmic Microwave Background Temperature at Galaxy Clusters

We have deduced the cosmic microwave background temperature in the Coma Cluster (A1656, z = 0.0231) and in A2163 (z = 0.203) from spectral measurements of the Sunyaev-Zeldovich (SZ) effect over four passbands at radio and microwave frequencies. The resulting temperatures at these redshifts are TComa = 2.789 K and TA2163 = 3.377 K, respectively. These values confirm the expected relation T(z) = T0(1 + z), where T0 = 2.725 ± 0.002 K is the value measured by the COBE Far Infrared Absolute Spectrometer experiment. Alternative scaling relations that are conjectured in nonstandard cosmologies can be constrained by the data; for example, if T(z) = T0(1 + z)1-a or T(z) = T0[1 + (1 + d)z], then a = -0.16 and d = 0.17 ± 0.36 (at 95% confidence). We briefly discuss future prospects for more precise SZ measurements of T(z) at higher redshifts.

Molecular Signals from Primordial Clouds at High Redshift

The possibility to detect cosmological signals from the post-recombination Universe is one of the main aims of modern cosmology. In a previous paper we emphasized the role that elastic resonant scattering through LiH molecules can have in dumping primary CBR anisotropies and raising secondary signals. Here we extend our analysis to all the evolutionary stages of a primordial cloud, starting with the linear phase, through the turn-around and to the non linear collapse. We have done calculations for proto-clouds in a CDM scenario and, more generally, for a set of clouds with various masses and various turn-around redshifts, in this case without referring to any particular structure formation scenario. We found that the first phase of collapse, for

Fluctuations in the microwave background at intermediate angular scales

t/t_{free-fall}=0.05\div 0.2

Mapping the CMB sky: The BOOMERanG experiment

is the best one for simultaneous detection of the first two LiH rotational lines. The observational frequency falls between 30 and 250 GHz and the line width

Millimeter observation of the SZ effect in the corona borealis supercluster

{\Delta \nu\over \nu}

A ground-based experiment for CMBR anisotropy observations: MITO

is between

Polarization properties of Fluorogold∗ in the far-infrared☆

10^{-5}

Testing the isotropy of the cosmic microwave background - the ULISSE Experiment

and

A short-wavelength measurement of the cosmic background radiation anisotropy

10^{-4}