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In simulations of some infinite range spin glass systems with finite connectivity, it is found that for any resonable computational time, the saturatedenergy per spin that is achieved by a cluster algorithm is lowered in comparison to that…

Condensed Matter · Physics 2016-08-31 N. Persky , I. Kanter , S. Solomon

A new approach to clustering, based on the physical properties of inhomogeneous coupled chaotic maps, is presented. A chaotic map is assigned to each data-point and short range couplings are introduced. The stationary regime of the system…

Statistical Mechanics · Physics 2009-10-31 L. Angelini , F. De Carlo , C. Marangi , M. Pellicoro , S. Stramaglia

We estimate the distribution of intrinsic shapes of APM galaxy clusters from the distribution of their apparent shapes. We measure the projected cluster ellipticities using two alternative methods. The first method is based on moments of…

Astrophysics · Physics 2009-10-31 Spyros Basilakos , Manolis Plionis , Steve Maddox

We propose a novel method for multiple clustering that assumes a co-clustering structure (partitions in both rows and columns of the data matrix) in each view. The new method is applicable to high-dimensional data. It is based on a…

We propose an adaptive Metropolis-Hastings algorithm in which sampled data are used to update the proposal distribution. We use the samples found by the algorithm at a particular step to form the information-theoretically optimal mean-field…

Other Condensed Matter · Physics 2007-05-23 David H. Wolpert , Chiu Fan Lee

We study the CLASH sample of galaxy clusters using a new deprojection method for weak gravitational lensing observations. This method is non-parametric, allowing us to infer mass profiles, or equivalently circular velocities, without having…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-11 Tobias Mistele , Federico Lelli , Stacy McGaugh , James Schombert , Benoit Famaey

Clustering is indispensable for data analysis in many scientific disciplines. Detecting clusters from heavy noise remains challenging, particularly for high-dimensional sparse data. Based on graph-theoretic framework, the present paper…

Computer Vision and Pattern Recognition · Computer Science 2014-07-08 Deli Zhao , Xiaoou Tang

This paper considers a canonical clustering problem where one receives unlabeled samples drawn from a balanced mixture of two elliptical distributions and aims for a classifier to estimate the labels. Many popular methods including PCA and…

Machine Learning · Statistics 2021-11-30 Kaizheng Wang , Yuling Yan , Mateo Díaz

We aim to improve upon the exploration of the general-purpose random walk Metropolis algorithm when the target has non-convex support $A \subset \mathbb{R}^d$, by reusing proposals in $A^c$ which would otherwise be rejected. The algorithm…

Probability · Mathematics 2021-08-17 John Moriarty , Jure Vogrinc , Alessandro Zocca

Lensing by galaxy clusters is a versatile probe of cosmology and extragalactic astrophysics, but the accuracy of some of its predictions is limited by the simplified models adopted to reduce the (otherwise untractable) number of degrees of…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-28 Pietro Bergamini , Adriano Agnello , Gabriel Bartosch Caminha

Motivated by Bayesian inference with highly informative data we analyze the performance of random walk-like Metropolis-Hastings algorithms for approximate sampling of increasingly concentrating target distributions. We focus on Gaussian…

Computation · Statistics 2022-02-25 Daniel Rudolf , Björn Sprungk

We introduce a general semiparametric clusterwise elliptical distribution to assess how latent cluster structure shapes continuous outcomes. Using a subjectwise representation, we first estimate cluster-specific mean vectors and a…

Methodology · Statistics 2026-04-10 Jen-Chieh Teng , Sheng-Hsin Fan , Chin-Tsang Chiang , Ming-Yueh Huang , Alvin Lim

In the realm of big data, discerning patterns in nonlinear systems affected by external control inputs is increasingly challenging. Our approach blends the coarse-graining strengths of centroid-based unsupervised clustering with the clarity…

Fluid Dynamics · Physics 2023-12-25 Nitish Arya , Aditya G. Nair

Cosmological N-body simulations are crucial for understanding how the Universe evolves. Studying large-scale distributions of matter in these simulations and comparing them to observations usually involves detecting dense clusters of…

Astrophysics of Galaxies · Physics 2019-12-25 Aidan Reilly , Nikita Ivkin , Gerard Lemson , Vladimir Braverman , Alexander Szalay

This paper considers the problem of clustering a partially observed unweighted graph---i.e., one where for some node pairs we know there is an edge between them, for some others we know there is no edge, and for the remaining we do not know…

Machine Learning · Computer Science 2014-07-25 Yudong Chen , Ali Jalali , Sujay Sanghavi , Huan Xu

We investigate how observations of strong lensing can be used to infer cosmological parameters, in particular the equation of state of dark energy. We focus on the growth of the critical lines of lensing clusters with the source redshift as…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-03 Britta Zieser , Matthias Bartelmann

This paper introduces an elasticity reconstruction method based on local displacement observations of elastic bodies. Sparse reconstruction theory is applied to formulate the underdetermined inverse problems of elasticity reconstruction…

Machine Learning · Computer Science 2019-02-26 Megumi Nakao , Mitsuki Morita , Tetsuya Matsuda

We study the cluster recovery problem in the semi-supervised active clustering framework. Given a finite set of input points, and an oracle revealing whether any two points lie in the same cluster, our goal is to recover all clusters…

Machine Learning · Computer Science 2020-11-02 Marco Bressan , Nicolò Cesa-Bianchi , Silvio Lattanzi , Andrea Paudice

Identification of the clusters from an unlabeled data set is one of the most important problems in Unsupervised Machine Learning. The state of the art clustering algorithms are based on either the statistical properties or the geometric…

Machine Learning · Computer Science 2018-01-04 Sambarta Dasgupta , Keivan Ebrahimi , Umesh Vaidya

The inverse potential problem consists in determining the density of the volume potential from measurements outside the sources. Its ill-posedness is due both to the non-uniqueness of the solution and to the instability of the solution with…

Numerical Analysis · Mathematics 2025-10-07 P. N. Vabishchevich