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Related papers: Equivariant Estimation of Fr\'echet Means

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Empirical Likelihood (EL) is a type of nonparametric likelihood that is useful in many statistical inference problems, including confidence region construction and $k$-sample problems. It enjoys some remarkable theoretical properties,…

Statistics Theory · Mathematics 2024-12-30 Karthik Bharath , Huiling Le , Andrew T A Wood , Xi Yan

Amenable groups are those admitting an invariant mean -- a finitely additive probability mean that assigns equal ``weight'' to any two translates of the same set. We introduce coset correct means (CCMs), a class of finitely additive means…

Group Theory · Mathematics 2026-04-21 Armando Martino , Motiejus Valiunas

Mixture modelling using elliptical distributions promises enhanced robustness, flexibility and stability over the widely employed Gaussian mixture model (GMM). However, existing studies based on the elliptical mixture model (EMM) are…

Machine Learning · Computer Science 2020-09-30 Shengxi Li , Zeyang Yu , Danilo Mandic

A common feature of methods for analyzing samples of probability density functions is that they respect the geometry inherent to the space of densities. Once a metric is specified for this space, the Fr\'echet mean is typically used to…

Methodology · Statistics 2018-12-20 Alexander Petersen , Hans-Georg Müller

Equivariance of neural networks to transformations helps to improve their performance and reduce generalization error in computer vision tasks, as they apply to datasets presenting symmetries (e.g. scalings, rotations, translations). The…

Computer Vision and Pattern Recognition · Computer Science 2022-11-08 Mateus Sangalli , Samy Blusseau , Santiago Velasco-Forero , Jesus Angulo

This paper considers statistical estimation problems where the probability distribution of the observed random variable is invariant with respect to actions of a finite topological group. It is shown that any such distribution must satisfy…

Machine Learning · Statistics 2015-06-23 Yu-Hui Chen , Dennis Wei , Gregory Newstadt , Marc DeGraef , Jeffrey Simmons , Alfred Hero

We propose a robust and scalable procedure for general optimization and inference problems on manifolds leveraging the classical idea of `median-of-means' estimation. This is motivated by ubiquitous examples and applications in modern data…

Methodology · Statistics 2020-06-16 Lizhen Lin , Drew Lazar , Bayan Sarpabayeva , David B. Dunson

The approximation of probability measures on compact metric spaces and in particular on Riemannian manifoldsby atomic or empirical ones is a classical task in approximation and complexity theory with a wide range of applications. Instead of…

Optimization and Control · Mathematics 2021-01-12 Martin Ehler , Manuel Gräf , Sebastian Neumayer , Gabriele Steidl

As quantum tomography is becoming a key component of the quantum engineering toolbox, there is a need for a deeper understanding of the multitude of estimation methods available. Here we investigate and compare several such methods: maximum…

Quantum Physics · Physics 2019-05-22 Anirudh Acharya , Theodore Kypraios , Madalin Guta

Frame theory is a powerful tool in the domain of signal processing and communication. Among its numerous configurations, the ones which have drawn much attention recently are Equiangular Tight Frame (ETF) and Grassmannian Frame. These…

Information Theory · Computer Science 2013-07-02 Hailong Shi , Hao Zhang

In recent years, deep learning techniques have shown great success in various tasks related to inverse problems, where a target quantity of interest can only be observed through indirect measurements by a forward operator. Common approaches…

Numerical Analysis · Mathematics 2024-03-18 Matthias Beckmann , Nick Heilenkötter

There is growing interest in developing statistical estimators that achieve exponential concentration around a population target even when the data distribution has heavier than exponential tails. More recent activity has focused on…

Statistics Theory · Mathematics 2025-04-22 Jakwang Kim , Jiyoung Park , Anirban Bhattacharya

We study curvature invariants of a sub-Riemannian manifold (i.e., a manifold with a Riemannian metric on a non-holonomic distribution) related to mutual curvature of several pairwise orthogonal subspaces of the distribution, and prove…

Differential Geometry · Mathematics 2022-12-27 Vladimir Rovenski

Two central limit theorems for sample Fr\'echet means are derived, both significant for nonparametric inference on non-Euclidean spaces. The first one, Theorem 2.2, encompasses and improves upon most earlier CLTs on Fr\'echet means and…

Statistics Theory · Mathematics 2016-03-29 Rabi Bhattacharya , Lizhen Lin

We consider semiparametric moment condition models invariant to transformation groups. The parameter of interest is estimated by minimum empirical divergence approach, introduced by Broniatowski and Keziou (2012). It is shown that the…

Statistics Theory · Mathematics 2024-08-21 Michel Broniatowski , Jana Jurečková , Amor Keziou

Measure Equivalence (ME) is the measure theoretic counterpart of quasi-isometry. This field grew considerably during the last years, developing tools to distinguish between different ME classes of countable groups. On the other hand,…

Dynamical Systems · Mathematics 2007-05-23 Damien Gaboriau

To characterize the location (mean, median) of a set of graphs, one needs a notion of centrality that is adapted to metric spaces, since graph sets are not Euclidean spaces. A standard approach is to consider the Frechet mean. In this work,…

Machine Learning · Statistics 2022-01-19 Daniel Ferguson , Francois G. Meyer

The variance of noise plays an important role in many change-point detection procedures and the associated inferences. Most commonly used variance estimators require strong assumptions on the true mean structure or normality of the error…

Methodology · Statistics 2023-11-17 Ning Hao , Yue Selena Niu , Han Xiao

In many real-world applications of regression, conditional probability estimation, and uncertainty quantification, exploiting symmetries rooted in physics or geometry can dramatically improve generalization and sample efficiency. While…

Machine Learning · Computer Science 2025-05-28 Daniel Ordoñez-Apraez , Vladimir Kostić , Alek Fröhlich , Vivien Brandt , Karim Lounici , Massimiliano Pontil

Random objects are complex non-Euclidean data taking value in general metric space, possibly devoid of any underlying vector space structure. Such data are getting increasingly abundant with the rapid advancement in technology. Examples…

Methodology · Statistics 2023-10-13 Satarupa Bhattacharjee , Bing Li , Lingzhou Xue