English
Related papers

Related papers: On the linear term correction for needlets/wavelet…

200 papers

We analyze the 3-year WMAP data and look for a deviation from Gaussianity in the form of a 3-point function that has either of the two theoretically motivated shapes: local and equilateral. There is no evidence of departure from Gaussianity…

Astrophysics · Physics 2009-11-11 Paolo Creminelli , Leonardo Senatore , Matias Zaldarriaga , Max Tegmark

Various data analyses of the Cosmic Microwave Background (CMB) provide observational hints of statistical isotropy breaking. Some of these features can be studied within the framework of primordial vector fields in inflationary theories…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 N. Bartolo , E. Dimastrogiovanni , M. Liguori , S. Matarrese , A. Riotto

Non-data-aided (NDA) parameter estimation is considered for binary-phase-shift-keying transmission in an additive white Gaussian noise channel. Cramer-Rao lower bounds (CRLBs) for signal amplitude, noise variance, channel reliability…

Information Theory · Computer Science 2007-07-13 Fredrik Brannstrom , Lars K. Rasmussen

Minimum-variance estimators for the parameter fnl that quantifies local-model non-Gaussianity can be constructed from the cosmic microwave background (CMB) bispectrum (three-point function) and also from the trispectrum (four-point…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-03 Marc Kamionkowski , Tristan L. Smith , Alan Heavens

We present a Gaussianity analysis of the Archeops Cosmic Microwave Background (CMB) temperature anisotropy data maps at high resolution to constrain the non-linear coupling parameter fnl characterising well motivated non-Gaussian CMB…

Strong foreground contamination in high resolution CMB data requires masking which introduces statistical anisotropies and renders a full maximum likelihood analysis numerically intractable. Standard analysis methods like the pseudo-C_l…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-26 H. F. Gruetjen , E. P. S. Shellard

We study the impact of cosmological parameters' uncertainties on estimates of the primordial NG parameter f_NL in local and equilateral models of non-Gaussianity. We show that propagating these errors increases the f_NL relative uncertainty…

Astrophysics · Physics 2008-12-30 M. Liguori , A. Riotto

We develop a new Bayesian method for estimating white noise levels in CMB sky maps, and apply this algorithm to the 5-year WMAP data. We assume that the amplitude of the noise RMS is scaled by a constant value, alpha, relative to a…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-24 N. E. Groeneboom , H. K. Eriksen , K. Gorski , G. Huey , J. Jewell , B. Wandelt

The spectral variation of the cosmic microwave background (CMB) as observed by WMAP was tested using foreground reduced WMAP5 data, by producing subtraction maps at the 1$^\circ$ angular resolution between the two cosmological bands of V…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Bi-Zhu Jiang , Richard Lieu , Shuang-Nan Zhang , Bart Wakker

Bias due to imperfect shear calibration is the biggest obstacle when constraints on cosmological parameters are to be extracted from large area weak lensing surveys such as Pan-STARRS-3pi, DES or future satellite missions like Euclid. We…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-04 D. Gruen , S. Seitz , J. Koppenhoefer , A. Riffeser

In this paper, we consider an unknown functional estimation problem in a general nonparametric regression model with the feature of having both multiplicative and additive noise.We propose two new wavelet estimators in this general context.…

Statistics Theory · Mathematics 2020-12-25 Christophe Chesneau , Salima El Kolei , Junke Kou , Fabien Navarro

A simple cosmological model with only six parameters (matter density, Omega_m h^2, baryon density, Omega_b h^2, Hubble Constant, H_0, amplitude of fluctuations, sigma_8, optical depth, tau, and a slope for the scalar perturbation spectrum,…

The remarkable improvement in the estimates of different cosmological parameters in recent years has been largely spearheaded by accurate measurements of the angular power spectrum of Cosmic Microwave Background (CMB) radiation. This has…

Astrophysics · Physics 2011-04-11 Tarun Souradeep , Rajib Saha , Pankaj Jain

Measuring the three-point correlators of the Cosmic Microwave Background (CMB) anisotropies could help to get a handle on the level of non-Gaussianity present in the observational datasets and therefore would strongly constrain models of…

Astrophysics · Physics 2008-11-26 Alejandro Gangui , Jerome Martin

Primordial non-Gaussianity can source $\mu$-distortion anisotropies that are correlated with the large-scale temperature and polarization signals of the cosmic microwave background (CMB). A measurement of $\mu T$ and $\mu E$ correlations…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Aditya Rotti , Andrea Ravenni , Jens Chluba

Cosmic microwave background (CMB) lensing is an integrated effect whose kernel is greater than half the peak value in the range $1<z<5$. Measuring this effect offers a powerful tool to probe the large-scale structure of the Universe at high…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-27 Toshiya Namikawa , Benjamin Bose , François R. Bouchet , Ryuichi Takahashi , Atsushi Taruya

This paper provides full sky maps of foreground emission in all WMAP channels, with very low residual contamination from the Cosmic Microwave Background (CMB) anisotropies and controlled level of instrumental noise. Foreground maps are…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-25 Tuhin Ghosh , Jacques Delabrouille , Mathieu Remazeilles , Jean-Francois Cardoso , Tarun Souradeep

We use a separable mode expansion estimator with WMAP data to estimate the bispectrum for all the primary families of non-Gaussian models. We review the late-time mode expansion estimator methodology which can be applied to any…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 J. R. Fergusson , M. Liguori , E. P. S. Shellard

We search for planar deviations of statistical isotropy in the Wilkinson Microwave Anisotropy Probe (WMAP) data by applying a recently introduced angular-planar statistics both to full-sky and to masked temperature maps, including in our…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 L. Raul Abramo , Armando Bernui , Thiago S. Pereira

In this paper, we study the problem of estimation and learning under temporal distribution shift. Consider an observation sequence of length $n$, which is a noisy realization of a time-varying groundtruth sequence. Our focus is to develop…

Machine Learning · Computer Science 2025-05-22 Dheeraj Baby , Yifei Tang , Hieu Duy Nguyen , Yu-Xiang Wang , Rohit Pyati
‹ Prev 1 3 4 5 6 7 10 Next ›