نتایج جستجو برای: cosmic microwave background cmb

تعداد نتایج: 905952  

2002
E. M. Leitch

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...

2004
Amir Hajian Tarun Souradeep Neil Cornish

The statistical expectation values of the temperature fluctuations of the cosmic microwave background (CMB) are assumed to be preserved under rotations of the sky. We investigate the statistical isotropy (SI) of the CMB anisotropy maps recently measured by the Wilkinson Microwave Anisotropy Probe (WMAP) using Bipolar Power Spectrum (BiPS) proposed in (Hajian & Souradeep 2003b). The method can p...

2001
Michael S. Turner

Age consistency for the Universe today has been an important cosmological test. Even more powerful consistency tests at times as early as 10−32 sec lie ahead in the precision era of cosmology. I outline tests based upon cosmic microwave background (CMB) anisotropy, bigbang nucleosynthesis (BBN), particle dark matter, phase transitions, and inflation. The ultimate cosmic timescale – the fate of ...

2009
Chia-Min Lin

In this paper, we show that if we extend D-term hybrid inflation by adding a light scalar field which couples to a waterfall field, large non-Gaussianity can be generated at the end of inflation. Contribution of cosmic strings generated after D-term inflation to the Cosmic Microwave Background (CMB) angular power spectrum can be as low as 10% and this also evade the spectral index problem. cmli...

1993
Mark Hindmarsh

The Cosmic Microwave Background (CMB) fluctuations at very small angular scales (less than 10) induced by matter sources are computed in a simplified way. The result corrects a previous formula appearing in the literature. The small scale power spectrum from cosmic strings is then calculated by a new analytic method. The result compares extremely well with the spectrum computed by numerical tec...

2008
Peter Kramer

1 Abstract. Fluctuations of the Cosmic Microwave Background CMB are observed by the WMAP. When expanded into the harmonic eigenmodes of the space part of a cosmological model, they provide insight into the large-scale topology of space. All harmonic polynomials on the multiply connected dodecahedral Poincaré space are constructed. Strong and specific selection rules are given by comparing the p...

2008
AMIR HAJIAN TARUN SOURADEEP NEIL CORNISH

The statistical expectation values of the temperature fluctuations of the cosmic microwave background (CMB) are assumed to be preserved under rotations of the sky. We use the bipolar power s pectrum (BiPS) proposed in Hajian & Souradeep to investigate the statistical isotropy (SI) of the CMB anisotropy maps recently measured by the Wilkinson Microwave Anisotropy Probe (WMAP). The method can iso...

2008
Michel Lamarre

Fig. 2:The power spectrum of CMB anisotropies as seen by BOOMEranG.The first peak corresponds to an angular scale of about 1degree as predicted for it "flat Universe" (i.e., a Universe where the spatial part of the metric is Euclidean). ';2 4000 .3 Fig. 1: Map of the Cosmic Microwave Background obtained by the BOOMERanG experiment.The one-degree-Iike bumps ofthe CMS emission are tiny local fluc...

2008
Z. Staniszewski

In this paper, we present results from the complete set of cosmic microwave background (CMB) radiation temperature anisotropy observations made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR) operating at 150GHz. We include new data from the final 2005 observing season, expanding the number of detector-hours by 210% and the sky coverage by 490% over that used for the previous ACBA...

2007
Amir Hajian Carlos Hernández-Monteagudo Raul Jimenez David Spergel Licia Verde

We compute the effect of local electrons on the CMB temperature anisotropies. The number density and distribution of free electrons in our Galaxy has been accurately measured from pulsar dispersion measurements. Because of their distribution, the dynamics of our Galaxy, and the Galaxy peculiar velocity with respect to the Hubble flow, these free electrons leave a frequency-independent imprint o...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید