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A general inversion technique for the recovery of the underlying distribution function for observed galactic disks is presented and illustrated. Under the assumption that these disks are axi-symmetric and thin, the proposed method yields…

Astrophysics · Physics 2009-09-25 C. Pichon , E. Thiebaut

In order to study the galaxy population of galaxy clusters with photometric data one must be able to accurately discriminate between cluster members and non-members. The redMaPPer cluster finding algorithm treats this problem…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-19 Eduardo Rozo , Eli S. Rykoff , Matthew Becker , Rachel M. Reddick , Risa H. Wechsler

Clustering is often a challenging problem because of the inherent ambiguity in what the "correct" clustering should be. Even when the number of clusters $K$ is known, this ambiguity often still exists, particularly when there is variation…

Information Theory · Computer Science 2025-05-09 Kayvon Mazooji , Ilan Shomorony

We introduce a new, non-parametric method to infer deprojected 3D mass profiles $M(r)$ of galaxy clusters from weak gravitational lensing observations. The method assumes spherical symmetry and a moderately small convergence, $\kappa…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-20 Tobias Mistele , Amel Durakovic

Projection Pursuit is a classic exploratory technique for finding interesting projections of a dataset. We propose a method for recovering projections containing either Imbalanced Clusters or a Bernoulli-Rademacher distribution using a…

Machine Learning · Computer Science 2025-07-01 Martin Eppert , Satyaki Mukherjee , Debarghya Ghoshdastidar

We investigate the use of the Metropolis-Hastings algorithm to sample posterior distribution in a Bayesian inverse problem, where the likelihood function is random. Concretely, we consider the case where one has full field observations of a…

Numerical Analysis · Mathematics 2026-02-20 Emil Løvbak , Sebastian Krumscheid

The problem of clustering noisy and incompletely observed high-dimensional data points into a union of low-dimensional subspaces and a set of outliers is considered. The number of subspaces, their dimensions, and their orientations are…

Machine Learning · Statistics 2015-08-24 Reinhard Heckel , Helmut Bölcskei

A novel evolutionary method is introduced that can be used for constraining the parameters and theoretical models of Cosmology. The newly proposed algorithm, which is inherently parallel by design, is able to obtain the full potential of…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-28 Supin P Surendran , Aiswarya A , Rinsy Thomas , Minu Joy

Bayesian nonparametric mixture models are widely used to cluster observations. However, one major drawback of the approach is that the estimated partition often presents unbalanced clusters' frequencies with only a few dominating clusters…

Methodology · Statistics 2026-02-03 Beatrice Franzolini , Giovanni Rebaudo

Despite compelling theoretical arguments, the use of clusters as cosmological probes is, in practice, frequently questioned because of the many uncertainties impinging on cluster mass estimates. Our aim is to develop a fully self-consistent…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-29 M. Pierre , A. Valotti , L. Faccioli , N. Clerc , R. Gastaud , E. Koulouridis , F. Pacaud

We investigate the problem of exact cluster recovery using oracle queries. Previous results show that clusters in Euclidean spaces that are convex and separated with a margin can be reconstructed exactly using only $O(\log n)$ same-cluster…

Machine Learning · Computer Science 2021-07-14 Marco Bressan , Nicolò Cesa-Bianchi , Silvio Lattanzi , Andrea Paudice

The Metropolis-Hastings algorithm allows one to sample asymptotically from any probability distribution $\pi$. There has been recently much work devoted to the development of variants of the MH update which can handle scenarios where such…

Computation · Statistics 2018-03-28 Christophe Andrieu , Arnaud Doucet , Sinan Yıldırım , Nicolas Chopin

Traditional studies of stellar clusters in external galaxies use surface photometry and therefore focus on systems that are still bright and compact enough to be separated from the stellar background. Consequently, the latter stages of…

Astrophysics · Physics 2007-05-23 Anne Pellerin , Martin Meyer , Jason Harris , Daniela Calzetti

The problem of finding groups in data (cluster analysis) has been extensively studied by researchers from the fields of Statistics and Computer Science, among others. However, despite its popularity it is widely recognized that the…

Statistics Theory · Mathematics 2013-10-10 José E. Chacón

We use a matched filter algorithm to find and study clusters in both N-body simulations artificially populated with galaxies and the 2MASS survey. In addition to numerous checks of the matched filter algorithm, we present results on the…

Astrophysics · Physics 2008-11-07 C. S. Kochanek , Martin White , J. Huchra , L. Macri , T. H. Jarrett , S. E. Schneider , J. Mader

Context. Biases in mass measurements of galaxy clusters are one of the major limiting systematics in constraining cosmology with clusters. Aims. We aim to demonstrate that the systematics associated with cluster gravitational potentials are…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-04 C. Tchernin , E. T. Lau , S. Stapelberg , D. Hug , M. Bartelmann

We explore the potential of cross-correlating galaxies and peculiar velocities on non-linear scales to enhance cosmological constraints. Leveraging the \textsc{AbacusSummit} simulation suite and the halo occupation distribution (HOD)…

AIMS. While weak lensing cannot resolve cluster cores and strong lensing is almost insensitive to density profiles outside the scale radius, combinations of both effects promise to constrain density profiles of galaxy clusters well, and…

Astrophysics · Physics 2015-05-13 J. Merten , M. Cacciato , M. Meneghetti , C. Mignone , M. Bartelmann

We propose a novel distributed algorithm to cluster graphs. The algorithm recovers the solution obtained from spectral clustering without the need for expensive eigenvalue/vector computations. We prove that, by propagating waves through the…

Discrete Mathematics · Computer Science 2015-03-13 Tuhin Sahai , Alberto Speranzon , Andrzej Banaszuk

We develop a clustering framework for observations from a population with a smooth probability distribution function and derive its asymptotic properties. A clustering criterion based on a linear combination of order statistics is proposed.…

Statistics Theory · Mathematics 2013-04-16 Karthik Bharath , Vladimir Pozdnyakov , Dipak K Dey