English
Related papers

Related papers: Hierarchical Matching and Regression with Applicat…

200 papers

Knowing the redshift of galaxies is one of the first requirements of many cosmological experiments, and as it's impossible to perform spectroscopy for every galaxy being observed, photometric redshift (photo-z) estimations are still of…

Instrumentation and Methods for Astrophysics · Physics 2022-03-09 Ben Henghes , Connor Pettitt , Jeyan Thiyagalingam , Tony Hey , Ofer Lahav

In this paper, we motivate the use of galaxy clustering measurements using photometric redshift information, including a contribution from flux magnification, as a probe of cosmology. We present cosmological forecasts when clustering data…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Christopher Duncan , Benjamin Joachimi , Alan Heavens , Catherine Heymans , Hendrik Hildebrandt

Clustering is a fundamental analysis tool aiming at classifying data points into groups based on their similarity or distance. It has found successful applications in all natural and social sciences, including biology, physics, economics,…

Information Retrieval · Computer Science 2021-02-24 Wen-Bo Xie , Yan-Li Lee , Cong Wang , Duan-Bing Chen , Tao Zhou

We develop a new method which measures the projected density distribution w_p(r_p)n of photometric galaxies surrounding a set of spectroscopically-identified galaxies, and simultaneously the projected correlation function w_p(r_p) between…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Wenting Wang , Y. P. Jing , Cheng Li , Teppei Okumura , Jiaxin Han

Affinity propagation is an exemplar-based clustering algorithm that finds a set of data-points that best exemplify the data, and associates each datapoint with one exemplar. We extend affinity propagation in a principled way to solve the…

Machine Learning · Computer Science 2012-02-20 Inmar Givoni , Clement Chung , Brendan J. Frey

Broadband photometry offers a time and cost effective method to reconstruct the continuum emission of celestial objects. Thus, photometric redshift estimation has supported the scientific exploitation of extragalactic multiwavelength…

Astrophysics of Galaxies · Physics 2018-10-31 S. Fotopoulou , S. Paltani

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

Photometric galaxy surveys are an essential tool to further our understanding of the large-scale structure of the universe, its matter and energy content and its evolution. These surveys necessitate the determination of the galaxy redshifts…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-06 Pol Martí , Ramon Miquel , Anne Bauer , Enrique Gaztañaga

We study the clustering of galaxies detected at $i<22.5$ in the Science Verification observations of the Dark Energy Survey (DES). Two-point correlation functions are measured using $2.3\times 10^6$ galaxies over a contiguous 116 deg$^2$…

We estimate how clustering in large-scale redshift surveys can constrain various cosmological parameters. Depth and sky coverage of modern redshift surveys are greater than ever, opening new possibilities for statistical analysis. We have…

Astrophysics · Physics 2009-11-07 Takahiko Matsubara , Alexander S. Szalay

Photometric surveys produce large-area maps of the galaxy distribution, but with less accurate redshift information than is obtained from spectroscopic methods. Modern photometric redshift (photo-z) algorithms use galaxy magnitudes, or…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-15 J. Asorey , M. Carrasco Kind , I. Sevilla-Noarbe , R. J. Brunner , J. Thaler

A novel hierarchical search technique is presented for all-sky surveys for continuous gravitational-wave sources, such as rapidly spinning nonaxisymmetric neutron stars. Analyzing yearlong detector data sets over realistic ranges of…

General Relativity and Quantum Cosmology · Physics 2015-03-18 Holger J. Pletsch

Modern cosmological observations clearly reveal that the universe contains a hierarchy of clustering. However, recent surveys show a transition to homogeneity on large scales. The exact scale at which this transition occurs is still a topic…

Astrophysics · Physics 2007-05-23 Cristiano Sabiu

In cosmological analyses, precise redshift determination remains pivotal for understanding cosmic evolution. However, with only a fraction of galaxies having spectroscopic redshifts (spec-$z$s), the challenge lies in estimating redshifts…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-04 Anjitha John William , Priyanka Jalan , Maciej Bilicki , Wojciech A. Hellwing

Exploiting the full statistical power of future cosmic shear surveys will necessitate improvements to the accuracy with which the gravitational lensing signal is measured. We present a framework for calibrating shear with image simulations…

Hierarchical clustering is a stronger extension of one of today's most influential unsupervised learning methods: clustering. The goal of this method is to create a hierarchy of clusters, thus constructing cluster evolutionary history and…

Data Structures and Algorithms · Computer Science 2021-01-14 MohammadTaghi Hajiaghayi , Marina Knittel

Cosmological galaxy surveys aim at mapping the largest volumes to test models with techniques such as cluster abundance, cosmic shear correlations or baryon acoustic oscillations (BAO), which are designed to be independent of galaxy bias.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 E. Gaztanaga , M. Eriksen , M. Crocce , F. Castander , P. Fosalba , P. Marti , R. Miquel , A. Cabre

We present measurements of the redshift-dependent clustering of a DESI-like luminous red galaxy (LRG) sample selected from the Legacy Survey imaging dataset, and use the halo occupation distribution (HOD) framework to fit the clustering…

Determining accurate redshift distributions for very large samples of objects has become increasingly important in cosmology. We investigate the impact of extending cross-correlation based redshift distribution recovery methods to include…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Samuel Schmidt , Brice Ménard , Ryan Scranton , Christopher Morrison , Cameron McBride

We outline how redshift-space distortions (RSD) can be measured from the angular correlation function w({\theta}), of galaxies selected from photometric surveys. The natural degeneracy between RSD and galaxy bias can be minimized by…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 Ashley J Ross , Will J Percival , Martin Crocce , Anna Cabre , Enrique Gaztanaga