English
Related papers

Related papers: Denoising clustering covariance matrices with Rota…

200 papers

In photon-limited imaging, the pixel intensities are affected by photon count noise. Many applications, such as 3-D reconstruction using correlation analysis in X-ray free electron laser (XFEL) single molecule imaging, require an accurate…

Computer Vision and Pattern Recognition · Computer Science 2019-12-18 Zhizhen Zhao , Lydia T. Liu , Amit Singer

We propose a distributionally robust formulation for simultaneously estimating the covariance matrix and the precision matrix of a random vector.The proposed model minimizes the worst-case weighted sum of the Frobenius loss of the…

Machine Learning · Statistics 2025-11-19 Renjie Chen , Viet Anh Nguyen , Huifu Xu

As a classical problem, covariance estimation has drawn much attention from the statistical community for decades. Much work has been done under the frequentist and the Bayesian frameworks. Aiming to quantify the uncertainty of the…

Methodology · Statistics 2017-08-17 W. Jenny Shi , Jan Hannig , Randy C. S. Lai , Thomas C. M. Lee

This paper investigates regularized estimation of Kronecker-structured covariance matrices (CM) for polarization radar in sea clutter scenarios where the data are assumed to follow the complex, elliptically symmetric (CES) distributions…

Signal Processing · Electrical Eng. & Systems 2022-02-08 Lei Xie , Zishu He , Jun Tong , Tianle Liu , Jun Li , Jiangtao Xi

Most cluster randomized trials (CRTs) randomize fewer than 30-40 clusters in total. When performing inference for such ``small'' CRTs, it is important to use methods that appropriately account for the small sample size. When the generalized…

Methodology · Statistics 2025-12-01 Shifeng Sun , Xueqi Wang , Zhuoran Hou , Elizabeth L. Turner

Super sample covariance (SSC) is important when estimating covariance matrices using a set of mock catalogues for galaxy surveys. If the underlying cosmological simulations do not include the variation in background parameters appropriate…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-05 Greg Schreiner , Alex Krolewski , Shahab Joudaki , Will J. Percival

In the era of large surveys, yielding thousands of galaxy clusters, efficient mass proxies at all scales are necessary in order to fully utilize clusters as cosmological probes. At the cores of strong lensing clusters, the Einstein radius…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-21 J. D. Remolina González , K. Sharon , B. Reed , N. Li , G. Mahler , L. E. Bleem , M. Gladders , A. Niemiec , A. Acebron , H. Child

The disconnected part of the power spectrum covariance matrix (also known as the "Gaussian" covariance) is the dominant contribution on large scales for galaxy clustering and weak lensing datasets. The presence of a complicated sky mask…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-02 Carlos García-García , David Alonso , Emilio Bellini

Complementary views of galaxy clusters in the radio synchrotron, hard X-ray inverse Compton, and high-energy gamma-ray regimes are critical in calibrating them as high-precision cosmological probes. We present predictions for scaling…

Astrophysics · Physics 2009-11-13 Christoph Pfrommer

The launch of the Imaging X-ray Polarimetry Explorer (IXPE), the first space-based polarimeter since 1978, offers a two order of magnitude improvement to the measurement of X-ray polarisation than its predecessor OSO-8, offering…

High Energy Astrophysical Phenomena · Physics 2025-07-22 Melissa Ewing , Adam Ingram , John Rankin , Fabio Muleri

The goal of this study is to introduce a unified computational framework for simulating random iteration equations (RIE), understood as iteration equations containing random variables. The novelty of this work is that full probability…

Dynamical Systems · Mathematics 2026-04-08 Wolfgang Hoegele

Reinforcement learning (RL) has made significant advancements, achieving superhuman performance in various tasks. However, RL agents often operate under the assumption of environmental stationarity, which poses a great challenge to learning…

Machine Learning · Computer Science 2025-11-18 Guoqing Ma , Yuhan Zhang , Yuming Dai , Guangfu Hao , Yang Chen , Shan Yu

Gaussian graphical models are used for determining conditional relationships between variables. This is accomplished by identifying off-diagonal elements in the inverse-covariance matrix that are non-zero. When the ratio of variables (p) to…

Applications · Statistics 2018-08-07 Donald R. Williams , Juho Piironen , Aki Vehtari , Philippe Rast

We investigate simulation-based bandpower covariance matrices commonly used in cosmological parameter inferences such as the estimation of the tensor-to-scalar ratio $r$. We find that upper limits on $r$ can be biased low by tens of…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-06 Dominic Beck , Ari Cukierman , W. L. Kimmy Wu

This work provides a theoretical analysis for optimally solving the pose estimation problem using total least squares for vector observations from landmark features, which is central to applications involving simultaneous localization and…

Robotics · Computer Science 2022-10-24 Saeed Maleki , Adhiti Raman , Yang Cheng , John Crassidis , Matthias Schmid

One of the main unsolved problems of cosmology is how to maximize the extraction of information from nonlinear data. If the data are nonlinear the usual approach is to employ a sequence of statistics (N-point statistics, counting statistics…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-07 Uros Seljak , Grigor Aslanyan , Yu Feng , Chirag Modi

The application of standard sufficient dimension reduction methods for reducing the dimension space of predictors without losing regression information requires inverting the covariance matrix of the predictors. This has posed a number of…

Methodology · Statistics 2019-10-01 Kabir Opeyemi Olorede , Waheed Babatunde Yahya

This paper studies inference for quadratic forms of linear regression coefficients with clustered data and many covariates. Our framework covers three important special cases: instrumental variables regression with many instruments and…

Econometrics · Economics 2026-02-18 Michal Kolesár , Pengjin Min , Wenjie Wang , Yichong Zhang

Mixture model-based clustering has become an increasingly popular data analysis technique since its introduction over fifty years ago, and is now commonly utilized within a family setting. Families of mixture models arise when the component…

Methodology · Statistics 2019-11-11 Sanjeena Subedi , Paul D. McNicholas

Finite Gaussian mixture models are widely used for model-based clustering of continuous data. Nevertheless, since the number of model parameters scales quadratically with the number of variables, these models can be easily…

Methodology · Statistics 2018-09-25 Michael Fop , Thomas Brendan Murphy , Luca Scrucca
‹ Prev 1 4 5 6 7 8 10 Next ›