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We present a novel application of partial convolutional neural networks (PCNN) that can inpaint masked images of the cosmic microwave background. The network can reconstruct both the maps and the power spectra to a few percent for circular…

天体物理仪器与方法 · 物理学 2021-03-19 Gabriele Montefalcone , Maximilian H. Abitbol , Darsh Kodwani , R. D. P. Grumitt

We apply the Minkowski Tensor statistics to two dimensional slices of the three dimensional density field. The Minkowski Tensors are a set of functions that are sensitive to directionally dependent signals in the data, and furthermore can…

宇宙学与河外天体物理 · 物理学 2018-05-23 Stephen Appleby , Pravabati Chingangbam , Changbom Park , Sungwook E. Hong , Juhan Kim , Vidhya Ganesan

Two of the most commonly used tools to constrain the primordial non-Gaussianity are the bispectrum and the Minkowski functionals of CMB temperature anisotropies. These two measures of non-Gaussianity in principle provide distinct (though…

宇宙学与河外天体物理 · 物理学 2015-03-26 Wenjuan Fang , Adam Becker , Dragan Huterer , Eugene A. Lim

We investigate the use of wavelet transforms in detecting and characterising non-Gaussian structure in maps of the cosmic microwave background (CMB). We apply the method to simulated maps of the Kaiser-Stebbins effect due to cosmic strings…

天体物理学 · 物理学 2009-10-31 MP Hobson , AW Jones , AN Lasenby

We present a new method for time-efficient and accurate extraction of the power spectrum from future cosmic microwave background (CMB) maps based on properties of peaks and troughs of the Gaussian CMB sky. We construct a statistic…

天体物理学 · 物理学 2009-11-06 A. Kashlinsky , C. Hernández--Monteagudo , F. Atrio--Barandela

Secondary contributions to the anisotropy of the Cosmic Microwave Background (CMB), such as the integrated Sachs-Wolfe (ISW) effect, the thermal Sunyaev-Zel'dovich effect (tSZ), and the effect of gravitational lensing, have distinctive…

宇宙学与河外天体物理 · 物理学 2012-07-27 Dipak Munshi , Peter Coles , Alan Heavens

The next generation of CMB experiments can measure cosmological parameters with unprecedented accuracy - in principle. To achieve this in practice when faced with such gigantic data sets, elaborate data analysis methods are needed to make…

天体物理学 · 物理学 2009-10-28 Max Tegmark

We implement and further refine the recently proposed method (Kashlinsky, Hern\'andez-Monteagudo & Atrio-Barandela, 2001 - KHA) for a time efficient extraction of the power spectrum from future cosmic microwave background (CMB) maps. The…

天体物理学 · 物理学 2009-11-07 C. Hernandez-Monteagudo , A. Kashlinsky , F. Atrio-Barandela

Many problems arising in applications result in the need to probe a probability distribution for functions. Examples include Bayesian nonparametric statistics and conditioned diffusion processes. Standard MCMC algorithms typically become…

统计计算 · 统计学 2015-03-20 S. L. Cotter , G. O. Roberts , A. M. Stuart , D. White

Gaussianity of temperature fluctuations in the Cosmic Microwave Background(CMB) implies that the statistical properties of the temperature field can be completely characterized by its two point correlation function. The two point…

宇宙学与河外天体物理 · 物理学 2013-09-25 Nidhi Joshi , Aditya Rotti , Tarun Souradeep

We use Minkowski Functionals to explore the presence of non-Gaussian signatures in simulated cosmic microwave background (CMB) maps. Precisely, we analyse the non-Gaussianities produced from the angular power spectra emerging from a class…

宇宙学与河外天体物理 · 物理学 2023-03-08 Camila P. Novaes , Micol Benetti , Armando Bernui

One of the most powerful tools to probe the existence of cosmic defects in the early universe is through the Cosmic Microwave Background (CMB) radiation. It is well known that computations with causal sources are more involved than the…

天体物理学 · 物理学 2007-05-23 Alejandro Gangui

We present a method, based on the correlation function of excursion sets above a given threshold, to test the Gaussianity of the CMB temperature fluctuations in the sky. In particular, this method can be applied to discriminate between…

天体物理学 · 物理学 2009-10-30 R. B. Barreiro , J. L. Sanz , E. Martinez-Gonzalez , J. Silk

The measurements of CMB anisotropy have opened up a window for probing the global topology of the universe on length scales comparable to and beyond the Hubble radius. We have developed a new method for calculating the CMB anisotropy in…

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

We show how cosmological correlation functions of massless fields can be rewritten in terms of Minkowski correlation functions, by extracting symmetry-breaking operators from the cosmological correlators. This technique simplifies some…

高能物理 - 理论 · 物理学 2018-06-13 Shek Kit Chu , Mang Hei Gordon Lee , Shiyun Lu , Xi Tong , Yi Wang , Siyi Zhou

The recent progress in obtaining larger and deeper galaxy catalogues is of fundamental importance for cosmological studies, especially to robustly measure the large scale density fluctuations in the Universe. The present work uses the…

宇宙学与河外天体物理 · 物理学 2018-05-23 Camila P. Novaes , Armando Bernui , Henrique S. Xavier , Gabriela A. Marques

The K-means algorithm is among the most commonly used data clustering methods. However, the regular K-means can only be applied in the input space and it is applicable when clusters are linearly separable. The kernel K-means, which extends…

机器学习 · 计算机科学 2020-12-08 Amir Aradnia , Maryam Amir Haeri , Mohammad Mehdi Ebadzadeh

We use the analytical model recently introduced in Ref. \cite{lp92}, to investigate the statistics of temperature fluctuations on the cosmic microwave background (CMB), induced by topological defects. The cases of cosmic strings and…

高能物理 - 唯象学 · 物理学 2010-11-01 Leandros Perivolaropoulos

A simple method is presented for the rapid simulation of statistically-isotropic non-Gaussian maps of CMB temperature fluctuations with a given power spectrum and analytically-calculable bispectrum and higher-order polyspectra. The…

天体物理学 · 物理学 2009-11-10 Graca Rocha , M. P. Hobson , Sarah Smith , Pedro Ferreira , Anthony Challinor

We present an analysis of the Minkowski Functionals (MFs) describing the WMAP three-year temperature maps to place limits on possible levels of primordial non-Gaussianity. In particular, we apply perturbative formulae for the MFs to give…