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相关论文: Angular Power Spectrum Estimation using High Perfo…

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Redshift space distortions privilege the location of the observer in cosmological redshift surveys, breaking the translational symmetry of the underlying theory. This violation of statistical homogeneity has consequences for the modeling of…

宇宙学与河外天体物理 · 物理学 2018-03-23 Emanuele Castorina , Martin White

Spectrograph is an optical device that is used to disperse photons of different energies $E$ into distinct directions and space locations, and to take a snapshot of the whole spectrum of photon energies with a spatially sensitive photon…

光学 · 物理学 2015-06-03 Yuri Shvyd'ko

The "Tapered Gridded Estimator" (TGE) is a novel way to directly estimate the angular power spectrum from radio-interferometric visibility data that reduces the computation by efficiently gridding the data, consistently removes the noise…

宇宙学与河外天体物理 · 物理学 2017-07-27 Samir Choudhuri , Nirupam Roy , Somnath Bharadwaj , Sk. Saiyad Ali , Abhik Ghosh , Prasun Dutta

We present a new model of the diffuse Galactic synchrotron radiation, concentrating on its angular anisotropies. While previous studies have focussed on either the variation of the emissivity on large (kpc) scales, or on fluctuations due to…

星系天体物理 · 物理学 2013-06-26 Philipp Mertsch , Subir Sarkar

We point out that polarization measurements as planned for the upcoming PLANCK mission can significantly enhance the accuracy of cosmic parameter estimation compared to the temperature anisotropy spectrum alone. In order to illustrate this,…

天体物理学 · 物理学 2007-05-23 Pavel Naselsky , Jens Schmalzing , Jesper Sommer-Larsen , Steen Hannested

A large fraction of the information collected by cosmological surveys is simply discarded to avoid lengthscales which are difficult to model theoretically. We introduce a new technique which enables the extraction of useful information from…

宇宙学与河外天体物理 · 物理学 2013-10-08 Fergus Simpson , J. Berian James , Alan F. Heavens , Catherine Heymans

We investigate the possibility of detecting in redshift surveys a hemispherical power asymmetry similar to that first reported in CMB observations. We assume the hemispherical asymmetry arises from a linear gradient in comoving coordinates…

宇宙学与河外天体物理 · 物理学 2017-11-29 Zhongxu Zhai , Michael Blanton

Following on our purpose of developing a unified pipeline for large-scale structure data analysis with angular (i.e. harmonic-space) power spectra, we now include the weak lensing effect of magnification bias on galaxy clustering in a…

宇宙学与河外天体物理 · 物理学 2020-09-28 Konstantinos Tanidis , Stefano Camera , David Parkinson

We describe a fast and accurate method for estimation of the cosmic microwave background (CMB) anisotropy angular power spectrum --- Monte Carlo Apodised Spherical Transform EstimatoR. Originally devised for use in the interpretation of the…

天体物理学 · 物理学 2011-08-11 E. Hivon , K. M. Gorski , C. B. Netterfield , B. P. Crill , S. Prunet , F. Hansen

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

A grand challenge of the 21st century cosmology is to accurately estimate the cosmological parameters of our Universe. A major approach to estimating the cosmological parameters is to use the large-scale matter distribution of the Universe.…

宇宙学与河外天体物理 · 物理学 2017-11-07 Siamak Ravanbakhsh , Junier Oliva , Sebastien Fromenteau , Layne C. Price , Shirley Ho , Jeff Schneider , Barnabas Poczos

In this paper, we study how to directly measure the effect of peculiar velocities in the observed angular power spectra. We do this by constructing a new anti-symmetric estimator of Large Scale Structure using different dark matter tracers.…

宇宙学与河外天体物理 · 物理学 2021-12-03 José Fonseca , Chris Clarkson

Light beams carrying orbital angular momentum are key resources in modern photonics. In many applications, the ability of measuring the complex spectrum of structured light beams in terms of these fundamental modes is crucial. Here we…

We study the projected clustering of photometric luminous red galaxies from the DESI Legacy Survey, combining their angular power spectrum, bispectrum, and cross-correlation with maps of the CMB lensing convergence from the Planck…

宇宙学与河外天体物理 · 物理学 2025-10-21 Francesco Verdiani , Lea Harscouet , Matteo Zennaro , David Alonso , Boryana Hadzhiyska

A crucial issue in cosmology is the determination of the fluctuation power spectrum.The standard picture of the matter clustering, the Cold Dark Matter model (and its variant), assumes that,on scales smaller than a certain ``flattening…

天体物理学 · 物理学 2009-10-28 Francesco Sylos Labini , Luca Amendola

In this thesis we investigate several aspects related to the theory of fluctuations in the Cosmic Microwave Background. We develop a new algorithm to calculate the angular power spectrum of the anisotropies which is two orders of magnitude…

天体物理学 · 物理学 2007-05-23 Matias Zaldarriaga

Reliable extraction of cosmological information from observed cosmic microwave background (CMB) maps may require removal of strongly foreground contaminated regions from the analysis. In this article, we employ an artificial neural network…

宇宙学与河外天体物理 · 物理学 2023-03-13 Srikanta Pal , Pallav Chanda , Rajib Saha

Stars play a decisive role in our Universe, from its beginning throughout its complete evolution. For a thorough understanding of their properties, evolution, and physics of their outer envelopes, stellar spectra need to be analyzed by…

太阳与恒星天体物理 · 物理学 2024-09-06 Joachim Puls , Artemio Herrero , Carlos Allende Prieto

The Cosmic Microwave Background Radiation (CMBR) holds information about almost all the fundamental cosmological parameters, and by performing a likelihood analysis of high precision CMBR fluctuation data, these parameters can be inferred.…

天体物理学 · 物理学 2009-10-31 Steen Hannestad

Gaussianity and statistical isotropy of the Universe are modern cosmology's minimal set of hypotheses. In this work we introduce a new statistical test to detect observational deviations from this minimal set. By defining the temperature…

宇宙学与河外天体物理 · 物理学 2009-09-30 Thiago S. Pereira , L. Raul Abramo