نتایج جستجو برای: cosmic microwave background cmb

تعداد نتایج: 905952  

2001
B. S. MASON J. K. CARTWRIGHT S. PADIN T. J. PEARSON A. C. S. READHEAD J. SIEVERS P. UDOMPRASERT

The Cosmic Background Imager (CBI) is a 13-element interferometer designed to image intrinsic anisotropies in the cosmic microwave background (CMB) on arcminute scales. A review of the capabilities of the instrument is presented, together with a discussion of observations which have been taken over the past 9 months from the Atacama desert of Chile. We present preliminary high-resolution mosaic...

1999
K. Coble E. S. Cheng D. A. Cottingham D. J. Fixsen A. B. Goldin C. A. Inman M. S. Kowitt S. S. Meyer

We present new cosmic microwave background (CMB) anisotropy results from the combined analysis of the three flights of the first Medium Scale Anisotropy Measurement (MSAM1). This balloon-borne bolometric instrument measured about 10 square degrees of sky at half-degree resolution in 4 frequency bands from 5.2 cm to 20 cm with a high signal-to-noise ratio. Here we present an overview of our anal...

1998
Daniel J. Eisenstein Wayne Hu Max Tegmark

We show that the detection of acoustic oscillations in both upcoming cosmic microwave background (CMB) satellite experiments and large-redshift surveys can yield 5% determinations of and , an order-of-magnitude H Q 0 m improvement over CMB data alone. CMB anisotropies provide the sound horizon at recombination as a standard ruler. For reasonable baryon fractions, this scale is imprinted on the ...

2002
Alessandro Melchiorri

The last years have been an exciting period for the field of the Cosmic Microwave Background (CMB) research. With recent CMB balloon-borne and ground-based experiments we are entering a new era of ’precision’ cosmology that enables us to use the CMB anisotropy measurements to constrain the cosmological parameters and test new theoretical scenarios.

1998
Naoshi Sugiyama

Cosmic Microwave Background (CMB) anisotropies have been recognized as one of the most important observational quantities to understand the early stage of our universe. In this paper, recent development of theoretical works on CMB anisotropies are summarized and it is shown that temperature uctuations of CMB contain rich information, i.e., cosmological parameters, geometry of the universe, init...

Journal: :Physical review letters 2011
Blake D Sherwin Joanna Dunkley Sudeep Das John W Appel J Richard Bond C Sofia Carvalho Mark J Devlin Rolando Dünner Thomas Essinger-Hileman Joseph W Fowler Amir Hajian Mark Halpern Matthew Hasselfield Adam D Hincks Renée Hlozek John P Hughes Kent D Irwin Jeff Klein Arthur Kosowsky Tobias A Marriage Danica Marsden Kavilan Moodley Felipe Menanteau Michael D Niemack Michael R Nolta Lyman A Page Lucas Parker Erik D Reese Benjamin L Schmitt Neelima Sehgal Jon Sievers David N Spergel Suzanne T Staggs Daniel S Swetz Eric R Switzer Robert Thornton Katerina Visnjic Ed Wollack

For the first time, measurements of the cosmic microwave background radiation (CMB) alone favor cosmologies with w = -1 dark energy over models without dark energy at a 3.2-sigma level. We demonstrate this by combining the CMB lensing deflection power spectrum from the Atacama Cosmology Telescope with temperature and polarization power spectra from the Wilkinson Microwave Anisotropy Probe. The ...

1998
A. N. Lasenby A. W. Jones Y. Dabrowski

Observations of the Cosmic Microwave Background (CMB) are discussed, with particular emphasis on current ground-based experiments and on future satellite, balloon and interferometer experiments. Observational techniques and the effects of contaminating foregrounds are highlighted. Recent CMB data is used with large scale structure (LSS) data to constrain cosmological parameters and the compleme...

Journal: :Physical review letters 2002
Michael Kesden Asantha Cooray Marc Kamionkowski

Inflationary gravitational waves (GW) contribute to the curl component in the polarization of the cosmic microwave background (CMB). Cosmic shear--gravitational lensing of the CMB--converts a fraction of the dominant gradient polarization to the curl component. Higher-order correlations can be used to map the cosmic shear and subtract this contribution to the curl. Arcminute resolution will be ...

1998
Marc Kamionkowski

Much recent work on the cosmic microwave background (CMB) has focussed on the angular power spectrum of temperature anisotropies and particularly on the recovery of cosmological parameters from acoustic peaks in the power spectrum. However, there is more that can conceivably be done with CMB measurements. Here I briefly survey a few such ideas: cross-correlation with other cosmic backgrounds as...

Journal: :Physical review letters 1994
Bond Crittenden Davis Efstathiou Steinhardt

The cosmic microwave background anisotropy is sensitive to the slope and amplitude of primordial energy density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history, etc. In this Letter, we examine the degree to which these factors can be separately resolved from combined smalland large-angular scale anisotropy observati...

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