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相关论文: COBE Data Spatial--Frequency Analysis and CMB Anis…

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Since the measurements of COBE/FIRAS in the mid-90's we know that the energy spectrum of the cosmic microwave background (CMB) is extremely close to that of a perfect blackbody at an average temperature T0~2.726K. However, a number of…

宇宙学与河外天体物理 · 物理学 2018-06-11 Jens Chluba

We present the angular power spectrum derived from the first-year Wilkinson Microwave Anisotropy Probe (WMAP) sky maps. We study a variety of power spectrum estimation methods and data combinations and demonstrate that the results are…

We consider the possibility that the primordial curvature perturbation is direction-dependent. To first order this is parameterised by a quadrupolar modulation of the power spectrum and results in statistical anisotropy of the CMB, which…

宇宙学与河外天体物理 · 物理学 2018-02-15 Amel Durakovic , Paul Hunt , Suvodip Mukherjee , Subir Sarkar , Tarun Souradeep

We investigate the extent to which foreground cleaned CMB maps can be used to estimate the cosmological parameters at small scales. We use the SMICA method, a blind separation technique which works directly at the spectral level. In this…

宇宙学与河外天体物理 · 物理学 2019-04-17 C. Umiltà , J. F. Cardoso , K. Benabed , M. Le Jeune

We show that a good fitting to the first two years of {\it COBE}-DMR observations of the two-point angular correlation function of CBR temperature is given by models with a non-zero infrared cutoff $k_{min}$ in the spectrum of the…

天体物理学 · 物理学 2009-10-22 Yi-Peng Jing , Li-Zhi Fang

We review the relevant 10+ parameters associated with inflation and matter content; the relation between LSS and primary and secondary CMB anisotropy probes; COBE constraints on energy injection; current anisotropy band-powers which…

天体物理学 · 物理学 2009-10-30 J. Richard Bond , Andrew H. Jaffe

Spectral distortion anisotropies of the cosmic microwave background (CMB) provide a new probe of the early Universe that can be accessed using traditional CMB imaging techniques. It is possible to compute the creation and evolution of…

宇宙学与河外天体物理 · 物理学 2026-02-17 Jens Chluba , Sara Evangelista , Tom Daman , Geoff Vasil

Low amplitude (linear regime) cosmic density fluctuations lead to spatial variations in the locally measurable value of $H_0$ (denoted as $H_L$), $\delta_H \equiv (H_L-H_0)/H_0$, which are of order 3-6% (95% confidence interval) in a sphere…

天体物理学 · 物理学 2009-10-30 Yun Wang , David N. Spergel , Edwin L. Turner

The polarization of the Cosmic Microwave Background (CMB)is a powerful observational tool at hand for modern cosmology. It allows to break the degeneracy of fundamental cosmological parameters one cannot obtain using only anisotropy data…

天体物理学 · 物理学 2009-11-07 M. V. Sazhin , G. Sironi , O. S. Khovanskaya

We report improved measurements of temperature anisotropies in the cosmic microwave background (CMB) radiation made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR). In this paper, we use a new analysis technique and include…

We introduce a new technique to detect the discrete temperature steps that cosmic strings might have left in the cosmic microwave background (CMB) anisotropy map. The technique provides a validity test on the pattern search of cosmic…

天体物理学 · 物理学 2009-11-11 E. Jeong , G. F. Smoot

The COBE detection of CMB anisotropies provides the best way of fixing the amplitude of fluctuations on the largest scales. This normalization is usually given for an n=1 spectrum, including only the anisotropy caused by the Sachs- Wolfe…

天体物理学 · 物理学 2009-10-22 E. F. Bunn , D. Scott , M. White

The cosmic microwave background $B$-mode signal is potentially weaker than the diffuse Galactic foregrounds over most of the sky at any frequency. A common method of separating the CMB from these foregrounds is via pixel-based…

Destriping methods for constructing maps of the Cosmic Microwave Background (CMB) anisotropies have been investigated extensively in the literature. However, their error properties have been studied in less detail. Here we present an…

天体物理学 · 物理学 2009-11-10 G. Efstathiou

Anisotropies in the temperature of the cosmic microwave background have been detected on a range of scales by several different experiments. These anisotropies reflect the primordial spectrum of metric perturbations in the early universe.…

天体物理学 · 物理学 2009-10-22 Scott Dodelson , Arthur Kosowsky

We present the application of the Fast Independent Component Analysis ({\ica}) technique for blind component separation to polarized astrophysical emission. We study how the Cosmic Microwave Background (CMB) polarized signal, consisting of…

天体物理学 · 物理学 2009-06-16 C. Baccigalupi , F. Perrotta , G. De Zotti , G. F. Smoot , C. Burigana , D. Maino , L. Bedini , E. Salerno

We discuss the issue of how precisely we can measure the primordial power spectrum by using future observations of 21 cm fluctuations and cosmic microwave background (CMB). For this purpose, we investigate projected constraints on the…

宇宙学与河外天体物理 · 物理学 2015-06-15 Kazunori Kohri , Yoshihiko Oyama , Toyokazu Sekiguchi , Tomo Takahashi

Cosmic Microwave Background (CMB) anisotropies that result from quantum fluctuations during inflation are explored and the impact of their ``cosmic variance'' on the ability to use existing data to probe inflationary models is studied. We…

天体物理学 · 物理学 2016-08-30 Martin White , Lawrence M. Krauss , Joseph Silk

We use simulated maps of the cosmic microwave background anisotropy to quantify the ability of different statistical tests to discriminate between Gaussian and non-Gaussian models. Despite the central limit theorem on large angular scales,…

天体物理学 · 物理学 2009-10-31 Nicholas G. Phillips , A. Kogut

The (large angle) COBE DMR data can be used to probe the global topology of our universe on scales comparable to and just beyond the present ``horizon''. For compact topologies, the two main effects on the CMB are: [1] the breaking of…

天体物理学 · 物理学 2007-05-23 J. Richard Bond , Dmitry Pogosyan , Tarun Souradeep