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We study signatures in the Cosmic Microwave Background (CMB) induced by the presence of strong spatial curvature prior to the epoch of inflation which generated our present universe. If inflation does not last sufficiently long to drive the…

宇宙学与河外天体物理 · 物理学 2010-02-02 Tim Clunan , David Seery

We use wavelet and curvelet transforms to extract signals of cosmic strings from cosmic microwave background (CMB) temperature anisotropy maps, and to study the limits on the cosmic string tension which various ongoing CMB temperature…

宇宙学与河外天体物理 · 物理学 2017-06-21 Lukas Hergt , Adam Amara , Robert Brandenberger , Tomasz Kacprzak , Alexandre Refregier

Skewness of temperature fluctuations of the cosmic microwave background (CMB) produced by initially Gaussian adiabatic perturbations with the flat (Harrison-Zeldovich) spectrum, which arises due to non-linear corrections to a gravitational…

天体物理学 · 物理学 2009-10-28 Dipak Munshi , Tarun Souradeep , Alexei A. Starobinsky

A description of CMB temperature fluctuations beyond the power spectrum is important for verifying models of structure formation, especially in view of forthcoming high-resolution observations. We argue that higher-order statistics of…

天体物理学 · 物理学 2007-05-23 S. Winitzki , J. H. P. Wu

We present an extension of the ROMA map-making algorithm for the generation of optimal cosmic microwave background polarization maps. The new code allows for a possible cross-correlated noise component among the detectors of a CMB…

宇宙学与河外天体物理 · 物理学 2016-08-31 Giancarlo de Gasperis , Alessandro Buzzelli , Paolo Cabella , Paolo de Bernardis , Nicola Vittorio

We study the large-scale angular correlation signatures of the Cosmic Microwave Background (CMB) temperature fluctuations from WMAP data in several spherical cap regions of the celestial sphere, outside the Kp0 or Kp2 cut-sky masks. We…

天体物理学 · 物理学 2008-11-26 Armando Bernui , Thyrso Villela , Carlos A. Wuensche , Rodrigo Leonardi , Ivan Ferreira

We study future observational constraints on cosmic string parameters from various types of next-generation experiments: direct detection of gravitational waves (GWs), pulsar timing array, and the cosmic microwave background (CMB). We…

宇宙学与河外天体物理 · 物理学 2013-05-30 Sachiko Kuroyanagi , Koichi Miyamoto , Toyokazu Sekiguchi , Keitaro Takahashi , Joseph Silk

The identification of non-Gaussian signatures in cosmic microwave background (CMB) temperature maps is one of the main cosmological challenges today. We propose and investigate altenative methods to analyse CMB maps. Using the technique of…

天体物理学 · 物理学 2009-11-07 C. Raeth , P. Schuecker

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…

The statistical properties of a map of the primary fluctuations in the cosmic microwave background (CMB) may be specified to high accuracy by a few thousand power spectra measurements, provided the fluctuations are gaussian, yet the number…

天体物理学 · 物理学 2009-11-07 Sujata Gupta , Alan F. Heavens

We study synergies between three promising methods to measure $2<z<5$ large-scale structure in the next decade. Optical spectroscopic surveys are the most mature, but become increasingly difficult at $z>2$ and suffer from interloper…

宇宙学与河外天体物理 · 物理学 2019-07-24 Shi-Fan Chen , Emanuele Castorina , Martin White , Anže Slosar

Density perturbations at the decoupling epoch produce angular fluctuations in the temperature of the Cosmic Microwave Background (CMB) radiation that may appear as hot and cold spots. Observational data of the CMB includes instrumental…

天体物理学 · 物理学 2009-10-28 Laura Cayon , George Smoot

In this article, we extend previous studies based on CMB spherical harmonic phases (SHP) to examine the validity of the hypothesis that the temperature field of the CMB is consistent with a Gaussian random field (GRF). The null hypothesis…

宇宙学与河外天体物理 · 物理学 2022-01-11 Sarvesh Kumar Yadav , Rajib Saha

We continue our studies of the evolution and cosmological consequences of current-carrying cosmic string networks, described by a charge-velocity-dependent one scale (CVOS) model. We present a detailed calculation of the effects of these…

宇宙学与河外天体物理 · 物理学 2024-07-23 I. Yu. Rybak , C. J. A. P. Martins , Patrick Peter , E. P. S. Shellard

Observations from the first flight of the Medium Scale Anisotropy Measurement (MSAM) are analyzed to place limits on Gaussian fluctuations in the Cosmic Microwave Background Radiation (CMBR). This instrument chops a 30\arcmin\ beam in a 3…

The Cosmology Large Angular Scale Surveyor (CLASS) is a telescope array observing the Cosmic Microwave Background (CMB) at frequency bands centered near 40, 90, 150, and 220 GHz. CLASS measures the CMB polarization on the largest angular…

The Cosmic Microwave Background (CMB) reaches homogeneity at relatively modest angular scales compared to the expectation of the standard $\Lambda$CDM model revealing an important challenge to the theoretical predictions. We analyze this…

Secondary anisotropies of the cosmic microwave background (CMB) can be detected by using the cross-correlation between the large-scale structure (LSS) and the CMB temperature fluctuations. In such studies, chance correlations of primordial…

天体物理学 · 物理学 2009-02-26 Mona Frommert , Torsten A. Ensslin

We present a blind multi-detector multi-component spectral matching method for all sky observations of the cosmic microwave background, working on the spherical harmonics basis. The method allows to estimate on a set of observation maps the…

天体物理学 · 物理学 2007-05-23 G. Patanchon , H. Snoussi , J. F. Cardoso , J. Delabrouille

We generalize the concept of the ordinary skew-spectrum to probe the effect of non-Gaussianity on the morphology of Cosmic Microwave Background (CMB) maps in several domains: in real-space (where they are commonly known as…

宇宙学与河外天体物理 · 物理学 2015-05-20 Dipak Munshi , Joseph Smidt , Asantha Cooray , Alessandro Renzi , Alan Heavens , Peter Coles