English
Related papers

Related papers: Harmonic analysis of discrete tracers of large-sca…

200 papers

In the standard (classic) approach, galaxy clustering measurements from spectroscopic surveys are compressed into baryon acoustic oscillations and redshift space distortions measurements, which in turn can be compared to cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-28 Samuel Brieden , Héctor Gil-Marín , Licia Verde

We present a novel automatic adaptive aperture photometry algorithm for measuring the total magnitudes of merging galaxies with irregular shapes. First, we use a morphological pattern recognition routine for identifying the shape of an…

Instrumentation and Methods for Astrophysics · Physics 2017-02-08 Jen-Chao Huang , Chorng-Yuan Hwang

Upcoming large redshift surveys potentially allow precision measurements of the galaxy power spectrum. To accurately measure P(k) on the largest scales, comparable to the depth of the survey, it is crucial that finite volume effects are…

Astrophysics · Physics 2016-01-27 Max Tegmark

Algebraic Subspace Clustering (ASC) is a simple and elegant method based on polynomial fitting and differentiation for clustering noiseless data drawn from an arbitrary union of subspaces. In practice, however, ASC is limited to…

Computer Vision and Pattern Recognition · Computer Science 2015-10-16 Manolis C. Tsakiris , Rene Vidal

The angular power spectrum C_l is extracted from the 4 year COBE DMR data with a 20 degree galactic cut, using the narrowest window functions possible. The average power in eight multipole bands is also computed, and plotted together with a…

Astrophysics · Physics 2009-10-28 Max Tegmark

Many different techniques to analyze galaxy clustering data and obtain cosmological constraints have been proposed, tested and used. Given the large amount of data that will be available soon, it is worth investigating new observables and…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-23 Eleonora Vanzan , Alvise Raccanelli , Nicola Bartolo

It is common practice in cosmology to model large-scale structure observables as lognormal random fields, and this approach has been successfully applied in the past to the matter density and weak lensing convergence fields separately. We…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-18 Henrique S. Xavier , Filipe B. Abdalla , Benjamin Joachimi

Partial wave analysis is a key technique in hadron spectroscopy. The use of unbinned likelihood fits on large statistics data samples and ever more complex physics models makes this analysis technique computationally very expensive.…

Data Analysis, Statistics and Probability · Physics 2011-08-31 Niklaus Berger

Recent microscopy imaging techniques allow to precisely analyze cell morphology in 3D image data. To process the vast amount of image data generated by current digitized imaging techniques, automated approaches are demanded more than ever.…

Computer Vision and Pattern Recognition · Computer Science 2020-10-26 Dennis Eschweiler , Malte Rethwisch , Simon Koppers , Johannes Stegmaier

We perform a cosmic shear analysis in harmonic space using the first year of data collected by the Dark Energy Survey (DES-Y1). We measure the cosmic weak lensing shear power spectra using the Metacalibration catalogue and perform a…

Spectral clustering is one of the most popular clustering methods. However, the high computational cost due to the involved eigen-decomposition procedure can immediately hinder its applications in large-scale tasks. In this paper we use…

Machine Learning · Computer Science 2023-01-24 Yongyu Wang

Weak gravitational lensing surveys are rapidly becoming important tools to probe directly the mass density fluctuations in the universe and its background dynamics. Earlier studies have shown that it is possible to model the statistics of…

Astrophysics · Physics 2009-11-07 Patrick Valageas , Andrew J. Barber , Dipak Munshi

We introduce a spectral hierarchy of cosmic-web classifications obtained by applying simple scale-weighting kernels to the density field before performing a standard eigenvalue-based web classification. This unifies and extends several…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Francisco-Shu Kitaura , Francesco Sinigaglia

We present a new approach in modelling the polarized Galactic synchrotron emission in the microwave range (20-100 GHz), where this radiation is expected to play the leading role in contaminating the Cosmic Microwave Background (CMB) data.…

Astrophysics · Physics 2009-11-07 G. Bernardi , E. Carretti , R. Fabbri , C. Sbarra , S. Poppi , S. Cortiglioni

We examine the nature of galaxy clustering in redshift space using a method based on an expansion of the galaxian density field in Spherical Harmonics and linear theory. We derive a compact and self-consistent expression for the distortion…

Astrophysics · Physics 2007-05-23 Karl B. Fisher

Structural parameters are normally extracted from observed galaxies by fitting analytic light profiles to the observations. Obtaining accurate fits to high-resolution images is a computationally expensive task, requiring many model…

Instrumentation and Methods for Astrophysics · Physics 2015-03-17 Benjamin R. Barsdell , David G. Barnes , Christopher J. Fluke

Nowadays, analyzing and reducing the ever larger astronomical datasets is becoming a crucial challenge, especially for long cumulated observation times. The INTEGRAL/SPI X-gamma-ray spectrometer is an instrument for which it is essential to…

Instrumentation and Methods for Astrophysics · Physics 2013-05-27 L. Bouchet , P. Amestoy , A. Buttari , F. -H. Rouet , M. Chauvin

Spectral clustering algorithms typically require a priori selection of input parameters such as the number of clusters, a scaling parameter for the affinity measure, or ranges of these values for parameter tuning. Despite efforts for…

Machine Learning · Computer Science 2019-03-20 Milad Afzalan , Farrokh Jazizadeh

The present spatial distribution of galaxies in the Universe is non-Gaussian, with 40% skewness in 50 Mpc/h spheres, and remarkably little is known about the information encoded in it about cosmological parameters beyond the power spectrum.…

Astrophysics · Physics 2008-11-26 Emiliano Sefusatti , Martin Crocce , Sebastian Pueblas , Roman Scoccimarro