中文
相关论文

相关论文: The Oddly Quiet Universe: How the CMB challenges c…

200 篇论文

Following the recent measurement of the acoustic peak by the BOOMERanG and MAXIMA experiments in the CMB anisotropy angular power spectrum, many analyses have found that the geometry of the Universe is very close to flat, but slightly…

天体物理学 · 物理学 2009-10-31 Alessandro Melchiorri , Louise M. Griffiths

Recent satellite observations have revealed significant anisotropy in the cosmic microwave background (CMB) radiation, a phenomenon that had previously been detected but received limited attention due to its subtlety. With the advent of…

广义相对论与量子宇宙学 · 物理学 2025-02-10 S. Davood Sadatian , Amir Sabouri , Zahra Davari

Statistical Isotropy of the Cosmic Microwave Background (CMB) radiation has been studied and debated extensively in recent years. Under this assumption, the hot spots and cold spots of the CMB are expected to be uniformly distributed over a…

宇宙学与河外天体物理 · 物理学 2022-11-14 Md Ishaque Khan , Rajib Saha

The cosmic microwave background (CMB) radiation is characterized by well-established scales, the 2.7 K temperature of the Planckian spectrum and the $10^{-5}$ amplitude of the temperature anisotropy. These features were instrumental in…

We propose that several of the anomalies that have been observed at large angular scales in the CMB have a common origin in a cosmic bounce that took place before the inflationary era. The bounce introduces a new physical scale in the…

宇宙学与河外天体物理 · 物理学 2022-07-27 Ivan Agullo , Dimitrios Kranas , V. Sreenath

We study the apparent lack of power on large angular scales in the WMAP data. We confirm that although there is no apparent lack of power at large angular scales for the full-sky maps, the lowest multipoles of the WMAP data happen to have…

天体物理学 · 物理学 2007-05-23 Amir Hajian

We determine the full C_l spectra and correlation functions of the temperature and polarization anisotropies in the CMB, generated by a source modeled by the large N limit of spontaneously broken global O(N)-theories. We point out a problem…

宇宙学与河外天体物理 · 物理学 2015-06-17 Elisa Fenu , Daniel G. Figueroa , Ruth Durrer , Juan Garcia-Bellido , Martin Kunz

The peculiar motion of the Earth causes a dipole anisotropy modulation in the distant galaxy distribution due to the aberration effect. However, the amplitude and angular direction of the effect is not necessarily the same as those of the…

宇宙学与河外天体物理 · 物理学 2010-10-12 Yousuke Itoh , Kazuhiro Yahata , Masahiro Takada

We study the possibility for constraining the topology of the Universe by means of the matched circles statistic applied to polarised cosmic microwave background (CMB) anisotropy maps. The advantages of using the CMB polarisation maps in…

宇宙学与河外天体物理 · 物理学 2018-02-09 P. Bielewicz , A. J. Banday , K. M. Gorski

We develop the formalism necessary to study four-point functions of the cosmic microwave background (CMB) temperature and polarization fields. We determine the general form of CMB trispectra, with the constraints imposed by the assumption…

天体物理学 · 物理学 2011-05-12 Takemi Okamoto , Wayne Hu

The temperature fluctuations of the Cosmic Microwave Background (CMB) are supposed to be distributed randomly in both magnitude and phase, following to the simplest model of inflation. In this paper, we look at the odd and even multipoles…

宇宙学与河外天体物理 · 物理学 2015-03-19 M. Hansen , A. M. Frejsel , J. Kim , P. Naselsky , F. Nesti

Since WMAP and Planck some anomalous features appeared in the Cosmic Microwave Background (CMB) large-angle anisotropy, the so-called anomalies. One of these is the hemispherical power asymmetry, i.e. a difference in the average power on…

宇宙学与河外天体物理 · 物理学 2022-10-06 Giacomo Galloni , Nicola Bartolo , Sabino Matarrese , Marina Migliaccio , Angelo Ricciardone , Nicola Vittorio

We introduce an extension of the standard inflationary paradigm on which the big bang singularity is replaced by an anisotropic bounce. Unlike in the big bang model, cosmological perturbations find an adiabatic regime in the past. We show…

广义相对论与量子宇宙学 · 物理学 2020-07-13 Ivan Agullo , Javier Olmedo , V. Sreenath

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 analyse the anisotropy of the cosmic microwave background (CMB) in hyperbolic universes possessing a non-trivial topology with a fundamental cell having an infinitely long horn. The aim of this paper is twofold. On the one hand, we show…

天体物理学 · 物理学 2009-11-10 Ralf Aurich , Sven Lustig , Frank Steiner , Holger Then

The Cosmic Microwave Background (CMB) encodes information on the origin and evolution of the universe, buried in a fractional anisotropy of one part in 100,000 on angular scales from arcminutes to tens of degrees. We await the coming…

天体物理学 · 物理学 2007-05-23 J. Richard Bond , Robert G. Crittenden , Andrew H. Jaffe , Lloyd Knox

There are evidences that the cosmic microwave background (CMB) large-angle anomalies imply a departure from statistical isotropy and hence from the standard cosmological model. We propose a LCDM model extension whose dark energy component…

天体物理学 · 物理学 2008-11-26 Davi C. Rodrigues

We are in motion against the cosmic backdrop. This motion is evidenced by the systematic temperature shift - or dipole anisotropy - observed in the Cosmic Microwave Background radiation (CMB). Because of the Doppler effect, the temperature…

天体物理学 · 物理学 2015-06-24 Chris Blake , Jasper Wall

We present a pedagogical and phenomenological introduction to the study of cosmic microwave background (CMB) polarization to build intuition about the prospects and challenges facing its detection. Thomson scattering of temperature…

天体物理学 · 物理学 2009-08-18 Wayne Hu , Martin White

CMB anisotropy data could put powerful constraints on theories of the evolution of our Universe. Using the observations of the large number of CMB experiments, many studies have put constraints on cosmological parameters assuming different…

天体物理学 · 物理学 2015-06-24 Marian Douspis
‹ 上一页 1 8 9 10 下一页 ›