中文
相关论文

相关论文: An improved estimator for non-Gaussianity in cosmi…

200 篇论文

The primordial non-Gaussian parameter fNL has been shown to be scale-dependent in several models of inflation with a variable speed of sound. Starting from a simple ansatz for a scale-dependent amplitude of the primordial curvature…

宇宙学与河外天体物理 · 物理学 2010-01-06 Emiliano Sefusatti , Michele Liguori , Amit P. S. Yadav , Mark G. Jackson , Enrico Pajer

Upcoming cosmic microwave background (CMB) lensing measurements and tomographic galaxy surveys are expected to provide us with high-precision data sets in the coming years, thus paving the way for fruitful cross-correlation analyses. In…

宇宙学与河外天体物理 · 物理学 2022-07-27 Priyesh Chakraborty , Shu-Fan Chen , Cora Dvorkin

Two groups [3,4] have confirmed the results of our paper concerning the actual existence of low variance circles in the cosmic microwave background (CMB) sky. They also point out that the effect does not contradict the LCDM model - a matter…

宇宙学与河外天体物理 · 物理学 2010-12-08 V. G. Gurzadyan , R. Penrose

We continue the analysis of non-Gaussianities in the CMB by means of the scaling index method (SIM, Raeth, Schuecker & Banday 2007) by applying this method on the 5-year WMAP data. We compare each of the results with 1000 Monte Carlo…

宇宙学与河外天体物理 · 物理学 2011-07-14 G. Rossmanith , C. Raeth , A. J. Banday , G. Morfill

In the current era of high-precision CMB experiments, the imprint of gravitational lensing on the CMB temperature is exploited as a source of valuable information. Especially the reconstruction of the lensing potential power spectrum is of…

宇宙学与河外天体物理 · 物理学 2015-06-05 Philipp M. Merkel , Bjoern Malte Schaefer

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

In the last few decades, advances in observational cosmology have given us a standard model of cosmology. We know the content of the universe to within a few percent. With more ambitious experiments on the way, we hope to move beyond the…

宇宙学与河外天体物理 · 物理学 2011-09-26 Amit P. S. Yadav , Benjamin D. Wandelt

Recent reports of stochastic gravitational wave background from four independent pulsar-timing-array collaborations have renewed the interest in the cosmological gravitational wave background (CGWB), which is expected to open a new window…

宇宙学与河外天体物理 · 物理学 2025-01-09 Rong-Gen Cai , Shao-Jiang Wang , Zi-Yan Yuwen , Xiang-Xi Zeng

We present an upgraded combined estimator, based on Minkowski Functionals and Neural Networks, with excellent performance in detecting primordial non-Gaussianity in simulated maps that also contain a weighted mixture of Galactic…

宇宙学与河外天体物理 · 物理学 2015-10-07 C. P. Novaes , A. Bernui , I. S. Ferreira , C. A. Wuensche

A detection of the level of non-Gaussianity in the CMB data is essential to discriminate among inflationary models and also to test alternative primordial scenarios. However, the extraction of primordial non-Gaussianity is a difficult…

宇宙学与河外天体物理 · 物理学 2010-05-07 A. Bernui , M. J. Reboucas , A. F. F. Teixeira

We study the covariance in the angular power spectrum estimates of CMB fluctuations when the primordial fluctuations are non-Gaussian. The non-Gaussian covariance comes from a nonzero connected four-point correlation function -- or the…

宇宙学与河外天体物理 · 物理学 2020-04-07 Saroj Adhikari , Dragan Huterer

We address the dual challenge of estimating deviations from Gaussianity arising in models of the Early Universe, whilst retaining information necessary to assess whether a detection of non-Gaussianity is primordial. We do this by…

宇宙学与河外天体物理 · 物理学 2015-05-13 Dipak Munshi , Alan Heavens

We describe and discuss the application of Gumbel statistics, which model extreme events, to WMAP 5-year measurements of the cosmic microwave background. We find that temperature extrema of the CMB are well modelled by the Gumbel formalism…

宇宙学与河外天体物理 · 物理学 2015-06-01 Gatis Mikelsons , Joseph Silk , Joe Zuntz

We present an all-sky formalism for the Cosmic Microwave Background (CMB) bispectrum induced by the primordial non-Gaussianities not only in scalar but also in vector and tensor fluctuations. We find that the bispectrum can be formed in an…

宇宙学与河外天体物理 · 物理学 2015-03-17 Maresuke Shiraishi , Daisuke Nitta , Shuichiro Yokoyama , Kiyotomo Ichiki , Keitaro Takahashi

Evidences for late-time acceleration of the Universe are provided by multiple probes, such as Type Ia supernovae, the cosmic microwave background (CMB) and large-scale structure (LSS). In this work, we focus on the integrated Sachs--Wolfe…

宇宙学与河外天体物理 · 物理学 2016-07-27 E. Moura Santos , F. C. Carvalho , M. Penna-Lima , C. P. Novaes , C. A. Wuensche

We study different variants of the Gibbs sampler algorithm from the perspective of their applicability to the estimation of power spectra of the cosmic microwave background (CMB) anisotropies. These include approaches studied earlier in the…

宇宙学与河外天体物理 · 物理学 2022-05-13 Gabriel Ducrocq , Nicolas Chopin , Josquin Errard , Radek Stompor

Noise maps from CMB experiments are generally statistically anisotropic, due to scanning strategies, atmospheric conditions, or instrumental effects. Any mis-modeling of this complex noise can bias the reconstruction of the lensing…

宇宙学与河外天体物理 · 物理学 2025-11-03 Louis Legrand , Blake Sherwin , Anthony Challinor , Julien Carron , Gerrit S. Farren

The study of the Gaussianity of the cosmic microwave background (CMB) radiation is a key topic to understand the process of structure formation in the Universe. In this paper, we review a very useful tool to perform this type of analysis,…

天体物理学 · 物理学 2007-05-23 R. B. Barreiro , J. A. Rubino-Martin , E. Martinez-Gonzalez

The detection of primordial $B$-mode polarisation of the Cosmic Microwave Background (CMB) is a major observational goal in modern Cosmology, offering a potential window into inflationary physics through the measurement of the…

宇宙学与河外天体物理 · 物理学 2025-10-22 Claudio Ranucci , Alessandro Carones , Léo Vacher , Nicoletta Krachmalnicoff , Carlo Baccigalupi

Extragalactic foregrounds in temperature maps of the Cosmic Microwave Background (CMB) severely limit the ability of standard estimators to reconstruct the weak lensing potential. These foregrounds are not fully removable by multi-frequency…

宇宙学与河外天体物理 · 物理学 2020-12-03 Noah Sailer , Emmanuel Schaan , Simone Ferraro
‹ 上一页 1 8 9 10 下一页 ›