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We expect a detectable correlation between two seemingly unrelated quantities: the four point function of the cosmic microwave background (CMB) and the amplitude of flux decrements in quasar (QSO) spectra. The amplitude of CMB convergence…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-20 Alberto Vallinotto , Matteo Viel , Sudeep Das , David N. Spergel

(Summary) Using the conditional luminosity function (CLF) -- the luminosity distribution of galaxies in a dark matter halo -- as the fundamental building block, we present an empirical model for the galaxy distribution. The model…

Astrophysics · Physics 2009-11-13 Asantha Cooray

We present a new method aiming to simplify the cosmological analysis of X-ray cluster surveys. It is based on purely instrumental observable quantities, considered in a two-dimensional X-ray colour-magnitude diagram (hardness ratio versus…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Nicolas Clerc , Marguerite Pierre , Florian Pacaud , Tatyana Sadibekova

A power constrained sensor network that consists of multiple sensor nodes and a fusion center (FC) is considered, where the goal is to estimate a random parameter of interest. In contrast to the distributed framework, the sensor nodes may…

Information Theory · Computer Science 2012-07-03 Swarnendu Kar , Pramod K. Varshney

Consider a setting with multiple units (e.g., individuals, cohorts, geographic locations) and outcomes (e.g., treatments, times, items), where the goal is to learn a multivariate distribution for each unit-outcome entry, such as the…

Machine Learning · Statistics 2025-10-21 Kyuseong Choi , Jacob Feitelberg , Caleb Chin , Anish Agarwal , Raaz Dwivedi

Leveraging the Baryon Acoustic Oscillations (BAO) feature present in clustering 2-point statistics, we aim to measure cosmological distances independently of the underlying background cosmological model. However this inference is…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-19 Stefano Anselmi , Pier-Stefano Corasaniti , Ariel G. Sanchez , Glenn D. Starkman , Ravi K. Sheth , Idit Zehavi

We present measurements of the spatial mapping between (hot) baryons and the total matter in the Universe, via the cross-correlation between the thermal Sunyaev-Zeldovich (tSZ) map from Planck and the weak gravitational lensing maps from…

The two point correlation function (2PCF) is a powerful statistical tool to measure galaxy clustering. Although 2PCF has also been used to study the clustering of stars on parsec and sub-parsec scales, its physical implication is not clear…

Astrophysics of Galaxies · Physics 2024-02-02 Yike Zhang , Wenting Wang , Jiaxin Han , Xiaohu Yang , Vicente Rodriguez-Gomez , Carles G. Palau , Zhenlin Tan

Weak lensing (WL) clustering is studied using 2D (angular) coordinates, while redshift space distortions (RSD) and baryon acoustic oscillations (BAO) use 3D coordinates, which requires a model dependent conversion of angles and redshifts…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-06 Martin Eriksen , Enrique Gaztanaga

We present a new approach for quantifying the abundance of galaxy clusters and constraining cosmological parameters using dynamical measurements. In the standard method, galaxy line-of-sight (LOS) velocities, $v$, or velocity dispersions…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 M. Ntampaka , H. Trac , J. Cisewski , L. C. Price

The number density of galaxy clusters across mass and redshift has been established as a powerful cosmological probe. Cosmological analyses with galaxy clusters traditionally employ scaling relations. However, many challenges arise from…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-08 M. Kosiba , N. Cerardi , M. Pierre , F. Lanusse , C. Garrel , N. Werner , M. Shalak

Context. The spatial distribution of haloes in the Cosmic Web encodes a wealth of information about the underlying cosmological model. These haloes can be represented as nodes of a graph, whose structural properties reflect cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-01 Anton Rudakovskyi , Franco Vazza , Maksym Tsizh

We demonstrate that observations lacking reliable redshift information, such as photometric and radio continuum surveys, can produce robust measurements of cosmological parameters when empowered by clustering-based redshift estimation. This…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-10 Ely D. Kovetz , Alvise Raccanelli , Mubdi Rahman

In this article we compare the cross-correlation and breakfinder techniques applied to the measurements of redshifts from low-resolution spectra. We assume spectra obtained from multinarrowband imagery, a technique for multi-object…

Astrophysics · Physics 2009-10-28 R. Cabanac , E. F. Borra

Image subtraction in astronomy is a tool for transient object discovery and characterization, particularly useful in wide fields, and is well suited for moving or photometrically varying objects such as asteroids, extra-solar planets and…

Instrumentation and Methods for Astrophysics · Physics 2013-01-09 Steven Hartung

High-dimensional, large-sample astrophysical databases of galaxy clusters, such as the Chandra Deep Field South COMBO-17 database, provide measurements on many variables for thousands of galaxies and a range of redshifts. Current…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Elizabeth Martinez-Gomez , Mercedes T. Richards , Donald St. P. Richards

Galaxy clustering and galaxy-galaxy lensing probe the connection between galaxies and their dark matter haloes in complementary ways. On one hand, the halo occupation statistics inferred from the observed clustering properties of galaxies…

Astrophysics · Physics 2009-11-19 Marcello Cacciato , Frank C. van den Bosch , Surhud More , Ran Li , H. J. Mo , Xiaohu Yang

The ROSAT Deep Cluster Survey (RDCS) has provided a new large deep sample of X-ray selected galaxy clusters. Observables such as the flux number counts n(S), the redshift distribution n(z) and the X-ray luminosity function (XLF) over a…

Astrophysics · Physics 2009-10-31 S. Borgani , P. Rosati , P. Tozzi , C. Norman

Clustering-based Approximate Nearest Neighbor Search (ANNS) organizes a set of points into partitions, and searches only a few of them to find the nearest neighbors of a query. Despite its popularity, there are virtually no analytical tools…

Machine Learning · Computer Science 2026-02-19 Thomas Vecchiato , Sebastian Bruch

The wide-area imaging surveys with the {\it Herschel} Space Observatory at sub-mm wavelengths have now resulted in catalogs of order one hundred thousand dusty, star-burst galaxies. We make a statistical estimate of $N(z)$ using a…